Anode loop nitrogen concentration design method and fuel cell design system

Abstract

The present invention provides an anode loop nitrogen concentration design method and a fuel cell design system. In the first aspect, an anode loop nitrogen concentration design method is provided, which determines the flow rate and pressure of the anode loop based on the cathode loop operating parameters to calculate the anode loop nitrogen concentration. In the second aspect, a cathode tolerance pressure drop design method is provided, which determines the cathode loop operating parameters based on input parameters and calculates the cathode tolerance pressure drop through pressure drop transfer. In the third aspect, a fuel cell design system is provided, which determines the operating and equipment parameters of the cathode, anode, and cooling loop based on the parameters obtained from the anode loop nitrogen concentration and cathode tolerance pressure drop design. The present invention links the calculations of the anode, cathode, and cooling loops of the fuel cell system to achieve global optimization, and introduces nitrogen concentration calculation under dynamic correlation, thereby improving the stack efficiency of the anode hydrogen cycle. Furthermore, the parameters of each loop are linked to the equipment calculation, taking into account equipment efficiency, ensuring the reliability and safety of the system, high accuracy, and low cost.

Description

Technical Field

[0001] The present invention relates to H01M, and more particularly, to an anode loop nitrogen concentration design method and a fuel cell design system. Background Art

[0002] A fuel cell system is a power generation system consisting of a fuel cell stack, subsystem piping, and a control system. The materials and heat of each system component are interrelated. Only by comprehensively controlling the fuel cell feed and equipment operating conditions can the safe operation of the fuel cell system be guaranteed. However, during system design, due to the complexity of the relationship between various parameters and the limitations of the lack of internal mechanisms, a large number of experiments are generally used to debug the parameters. This results in high design costs, low efficiency, and the test data is difficult to be widely applied.

[0003] System development based on thermodynamic principles is conducive to improving the effectiveness and accuracy of system design. However, at present, it is only designed for local pipelines, such as CN101262068B, and it is difficult to consider the impact of local changes on other equipment. The limitations are large. For example, when designing the pipeline's boost system, it is difficult to take into account the impact of boosting on feed humidity; when designing the cathode flow, it is difficult to consider the impact of the stack transmembrane on the anode flow; when designing the cooling path temperature, the impact of temperature on the stack efficiency is ignored, etc. Moreover, designing without considering the overall situation may even reduce battery life and even cause safety accidents.

[0004] In addition, in practical applications, it is often necessary to introduce a circulation path at the anode to improve hydrogen utilization efficiency. However, current designs mainly focus on the open circuit of the fuel cell stack and rarely pay attention to the circulation path. Even in the circulation path design, a circulation rate that is too high can easily cause system burden, and a circulation rate that is too low can easily cause hydrogen waste. The current circulation design based on hydrogen concentration is greatly affected by the reaction and has low control reliability. Although the design based on nitrogen concentration has high stability, it is currently prone to over-regulation and low accuracy due to the lack of quantitative calculation of dynamic conditions and correlation with other components. How to accurately design the emission concentration of the circulation path has become the key to affecting hydrogen efficiency.

[0005] Therefore, how to design an anode circuit with high hydrogen utilization rate while taking into account the efficiency of the anode circuit circulation and the efficiency of other components of the fuel cell stack, and avoid safety, reliability and efficiency problems caused by low correlation between the design of various equipment and operating parameters of the system under complex conditions in actual applications, has become an urgent problem that needs to be solved. Summary of the Invention

[0006] In order to solve the above problems, the present invention provides an anode loop nitrogen concentration design method and a fuel cell design system, which uses the cathode circuit pressure to adjust the anode circulation ratio, so as to accurately calculate the anode circulation circuit nitrogen concentration under dynamic correlation, and uses the balance of the cathode and anode outlet water volume after the cycle to correlate the physical quantities of the cathode and anode pipelines of the stack, and uses the transmission of pressure drop and the principle of continuous fluid in each pipeline to link the pipeline operating parameters with the equipment parameters, thereby linking the physical quantities between the anode circuit, cathode circuit and cooling circuit of the fuel cell system. While ensuring the stable control of the efficiency and safety of the stack, the design of the parameters of each equipment circuit is taken into account, which can achieve high stack efficiency, accurate calculation, simple design method, low cost, and high flexibility in design for different scenarios.

[0007] The calculation order of the formula of the present invention is from front to back.

[0008] A first aspect of the present invention provides a method for designing nitrogen concentration in an anode circuit, comprising:

[0009] S1. According to the physical quantity of the cathode pipeline, the partial pressure law and the law of conservation of materials are used to determine the nitrogen volume N at the anode outlet. N2,aout , hydrogen volume at anode outlet N H2,aout , anode outlet water volume N H2O,aout , anode outlet pressure P aout , nitrogen gas volume at anode inlet N N2,ain , hydrogen volume at the anode inlet N H2,ain , anode inlet water volume N H2O,ain , anode inlet pressure P ain ;

[0010] In this way, the parameters of the cathode circuit can be linked to the calculation of the anode circuit, improving the global relevance of the system.

[0011] S2. Calculate the nitrogen concentration C in the anode circuit based on the flow rate, pressure, temperature of each component of the anode and cathode, as well as the anode return ratio. N2 =(1-Fa)*N N2,aout / (N N2,aout +N H2,aout +N H2O,aout )*P aout / R / (Th+b1)+Fa*N N2,ain / (N H2,ain +N N2,ain +N H2O,ain )*P ain / R / (Tc+b1);

[0012] where N N2,aout is the nitrogen volume at the anode outlet, N H2,aout is the amount of hydrogen at the anode outlet, N H2O,aoutis the anode outlet water volume, P aout is the anode outlet pressure, R is the gas constant, Th is the cooling path outlet temperature Th=Tc+ΔT, Tc is the cooling path inlet temperature, b1 is the temperature gradient, N N2,ain is the nitrogen volume at the anode inlet, N H2,ain is the amount of hydrogen at the anode inlet, N H2O,ain is the anode inlet water volume, P ain is the anode inlet pressure, and Fa is the anode reflux ratio.

[0013] Here, through simple linear calculations, gas constant equations and conservation of materials, the anode operating parameters such as the amount of hydrogen, nitrogen, water, temperature, and pressure at the anode inlet and outlet can be quickly calculated. These are used for the anode loop nitrogen concentration calculation in this step and the subsequent anode loop system operation and equipment parameter calculations. By considering the nitrogen concentrations at the anode inlet and outlet, a dynamic expression of nitrogen concentration changes can be provided.

[0014] As a preferred technical solution of the present invention, step S1 includes:

[0015] S1.1. Calculate the anode inlet pressure P according to the cathode inlet pressure and the stack transmembrane pressure drop. ain =P cin +ΔPT, where P cin is the cathode inlet pressure, ΔPT is the stack transmembrane pressure drop, P ain Anode inlet pressure;

[0016] S1.2. Calculate the anode outlet water ratio f based on the anode inlet pressure, viscosity of each component, anode outlet nitrogen ratio, and temperature. H2O =P sat,aout / P ain , anode outlet hydrogen ratio fh=1-fn*(1-f H2O )-f H2O , anode outlet volume V aout =(-(((θ H2,in +θ H2,out )*fh+(θ H2O,in +θ H2O,out )*f H2O +(θ N2,in +θ N2,out )*fn*(1-f H2O ))*ff / n)-((((θ H2,in +θ H2,out )*fh+(θ H2O,in +θ H2O,out )*f H2O +(θ N2,in +θ N2,out )*fn*(1-f H2O))*ff / n)^2-4*(fh*b2+(1-fh)*b3)*(-I / 2 / F*R*(Tc+b1) / P ain *ff*θ H2,in +b4*((θ H2,in +θ H2,out )*fh+(θ H2O,in +θ H2O,out )*f H2O +(θ N2,in +θ N2,out )*fn*(1-f H2O ))*ff / n))^0.5) / 2 / (fh*b2+(1-fh)*b3)+b4, anode outlet pressure drop ΔPa=fh*(b5*(V aout -b4)^2–b6*(V aout -b4)+b7)+(1-fh)*(b8*(V aout -b4)^2–b9*(V aout -b4)+b10), and anode outlet pressure P aout =P ain -ΔPa, where P sat,aout is the saturated vapor pressure at the anode outlet P sat,aout =10^(a1-a2 / (a3+Th+b1)), P ain is the anode inlet pressure, ΔPa is the anode outlet pressure drop, fn is the anode outlet nitrogen ratio, f H2O Anode outlet water ratio, fh anode outlet hydrogen ratio, V aout is the anode outlet volume, θ H2,in is the hydrogen inlet viscosity, θ H2,out is the hydrogen outlet viscosity, θ H2O,in is the water vapor inlet viscosity, θ H2O,out is the water vapor outlet viscosity, θ N2,in is the nitrogen inlet viscosity, θ N2,out is the nitrogen outlet viscosity, n is the number of cells, I is the current density, R is the gas constant, F is the Faraday coefficient, Tc is the cooling path inlet temperature, ff is the anode pressure drop coefficient, b1 is the temperature gradient, b2, b3, b4 are the cycle coefficients, b5, b6, b7, b8, b9, b10 are the pressurization coefficients, a1, a2, a3 are the empirical coefficients of saturated vapor pressure;

[0017] S1.3. Calculate the anode outlet hydrogen volume N based on the anode outlet total volume and the anode outlet hydrogen ratio. H2,aout =N aout *fh, and the amount of hydrogen at the anode inlet N H2,ain =N H2,aout +n*I / 2 / F, where N aoutis the total amount of anode outlet, fh is the hydrogen ratio of anode outlet, F is the Faraday coefficient, I is the stack current density, n is the number of cells, N H2,aout Anode outlet hydrogen volume, N H2,ain Anode inlet hydrogen volume;

[0018] S1.4. Calculate the nitrogen volume N at the anode outlet based on the ratio of hydrogen volume to nitrogen volume at the anode outlet. N2,aout = nitrogen gas volume at anode inlet N N2,ain =fn / (1-fn)*N H2,aout , where fn is the nitrogen ratio at the anode outlet, N N2,aout Anode outlet nitrogen volume, N N2,ain Anode inlet nitrogen volume;

[0019] S1.5. Calculate the anode outlet water volume N based on the anode outlet pressure, saturated vapor pressure, anode outlet hydrogen volume and nitrogen volume. H2O,aout = anode inlet water volume N H2O,ain =P sat,aout / P aout *(1-P sat,aout / P aout )*(N H2,aout +N N2,aout ), where P sat,aout is the saturated vapor pressure at the anode outlet, N H2,aout Anode outlet hydrogen volume, N N2,aout Anode outlet nitrogen volume, P aout Anode outlet pressure, N H2O,aout Anode outlet water volume;

[0020] Preferably, the total amount of anode outlet N in step S2.3 aout =V aout *P aout / R / (Th+b1), where Th is the cooling outlet temperature, b1 is the temperature gradient, R is the gas constant, V aout Anode outlet volume, P aout Anode outlet pressure;

[0021] Here, the oxygen inlet viscosity θ O2,in =a4 / (Tc+b1+a5)*((Tc+b1) / a6)^1.5, a4, a5, a6 are the oxygen viscosity coefficients, and the oxygen outlet viscosity θ O2,out =a4 / (Th+b1+a5)*((Th+b1) / a6)^1.5, nitrogen inlet viscosity θ N2,in =a7 / (Tc+b1+a8)*((Tc+b1) / a9)^1.5, a7, a8, a9 are the nitrogen viscosity coefficients, and the nitrogen outlet viscosity θ N2,out=a7 / (Th+b1+a8)*((Th+b1) / a9)^1.5, water vapor inlet viscosity θ H2O,in =(a10+a11*(Tc+b1)-a12*(Tc+b1)^2), a10, a11, a12 are the water vapor viscosity coefficients, and the water vapor outlet viscosity θ H2O,out =(a10+a11*(Th+b1)-a12*(Th+b1)^2), hydrogen inlet viscosity θ H2,in =a18 / (Tc+b1+a19)*((Tc+b1) / a20)^1.5, a18, a19, a20 are hydrogen viscosity coefficients, hydrogen outlet viscosity θ H2,out =a18 / (Th+b1+a19)*((Th+b1) / a20)^1.5;

[0022] As a preferred technical solution of the present invention, the step S2 calculates the nitrogen concentration C of the anode circuit. N2 Then calculate C N2 and target nitrogen concentration C N2,t The difference between |C N2 -C N2,t |, when |C N2 -C N2,t | is less than the threshold, it is judged to be converged and the calculation ends. N2 -C N2,t | is greater than or equal to the threshold, it is judged as non-convergence, and the nitrogen ratio at the anode outlet is updated fn=C N2,t / C N2 *fn, repeatedly calculate the anode loop nitrogen concentration. This allows accurate calculation of the anode loop nitrogen concentration under varying changes, influenced by the cathode line parameters, and thus accurately adjusts the amount of anode residual hydrogen circulation, effectively improving the efficiency of the anode circulation.

[0023] When calculating the nitrogen concentration, the cathode inlet pressure P cin , and the present invention designs a suitable P by cathode tolerance voltage drop design method cin , which is used to calculate the nitrogen concentration of the anode and obtain appropriate cathode design parameters, and promote the overall design and correlation of cathode and anode parameters.

[0024] A second aspect of the present invention provides a cathode tolerance voltage drop design method, characterized by comprising:

[0025] T1. Calculate the amount of nitrogen N at the cathode inlet based on the input parameters N2,cin , the amount of oxygen at the cathode inlet N O2,cin , total cathode outlet volume V cout , cathode outlet pressure P cout ;

[0026] In this way, the parameters of the cathode pipeline can be designed according to the input parameters such as current density I, voltage V, number of batteries n, etc., and the cathode design under different system power conditions can be output.

[0027] T2. Calculate the pressure drop ΔP at the wet gas end of the humidifier 增湿w =k1*V cout , humidifier wet end downstream pressure Pwo=P cout -ΔP 增湿w , cathode tube valve pressure drop ΔP 阀门 =(32*N O2,cin +28*N N2,cin )^2 / Pwo*k3, cathode outlet pipe pressure drop ΔP 出口管 =(32*N O2,cin +28*N N2,cin )^2 / P0*k4, and the pressure at the cathode outlet pipe Pend=P0+ΔP 出口管 , where ΔP 增湿w is the pressure drop at the wet gas end, k1 is the humidifier pressure drop coefficient, k3 is the valve pressure drop coefficient, k4 is the pipeline pressure drop coefficient, and P0 is the ambient pressure;

[0028] T3. Calculate the current cathode tolerance voltage drop ΔPerr=Pwo-ΔP 阀门 -Pend, to determine convergence, at the current ΔPerr 当前 and historical ΔPerr 历史 When the absolute value of the difference is less than the threshold, the calculation converges and ends. 当前 and historical ΔPerr 历史 If the absolute value of the difference is greater than or equal to the threshold and the calculation does not converge, update P cin =P cin -ΔPerr 当前 , repeat the cathode tolerance voltage drop calculation.

[0029] In this way, the operating parameters of the cathode pipeline can be designed through the pressure drop transmission of each device in the cathode pipeline, thereby ensuring the positive pressure flow of the cathode pipeline to meet the safety and efficient operation of the system.

[0030] As a preferred technical solution of the present invention, step T1 includes:

[0031] T1.1. Calculate the amount of oxygen at the cathode inlet N O2,cin =n*I / 4 / F*αc, the amount of oxygen at the cathode outlet N O2,cout =N O2,cin *(αc-1) / αc, where I is the stack current density, F is the Faraday coefficient, and αc is the cathode reaction coefficient;

[0032] T1.2. Calculate the amount of nitrogen at the cathode inlet NN2,cin = Nitrogen volume at cathode outlet N N2,cout =0.79 / 0.21*N O2,cin ;

[0033] T1.3. Calculate the humidifier temperature gradient T hum =a13*(N O2,cin +N N2,cin ), cathode inlet dew point temperature T dp,cin =Th+b1-T hum , cathode inlet water partial pressure P H2O,cin =10^(a1-a2 / (a3+T dp,cin )), cathode inlet water volume N H2O,cin =P H2O,cin / (P cin -P H2O,cin )*(N O2,cin +N N2,cin ), estimated water volume at cathode outlet N H2O,cout,app =P sat,cout / (P cin -P sat,cout )*(N O2,cout +N N2,cout ), and cathode stack voltage drop ΔPc=((N O2,cout *θ O2,out +N N2,out *θ N2,out +N H2O,cout,app *θ H2O,out )*R*(Tc+b1) / P cin +(N O2,cin *θ O2,in +N N2,cin *θ N2,in +N H2O,cin *θ H2O,in )*R*(Th+b1) / P cin )*fc / n, where the cathode outlet saturated vapor pressure P sat,cout =10^(a1-a2 / (a3+Th+b1)), b1 is the temperature gradient, Th is the cooling path outlet temperature, Tc is the cooling path inlet temperature, a1, a2, a3 are the empirical coefficients of saturated vapor pressure, R is the gas constant, a13 is the humidification coefficient, P cin Cathode inlet pressure, θ O2,out is the oxygen outlet viscosity, θ N2,out is the nitrogen outlet viscosity, θ H2O,out is the water vapor outlet viscosity, θ O2,in is the oxygen inlet viscosity, θ N2,in is the nitrogen inlet viscosity, θ H2O,in is the water vapor inlet viscosity, fc is the cathode voltage drop coefficient, and n is the number of cells;

[0034] T1.4. Calculate cathode outlet pressure P cout =P cin -ΔPc, and cathode outlet water volume N H2O,cout =P sat,cout / (P cout -P sat,cout )*(N O2,cout +N N2,cout );

[0035] T1.5. Calculate the total cathode outlet volume V cout =(N O2,cout +N N2,cout +N H2O,cout )*R*(Th+b1) / P cout .

[0036] Here, the cathode water volume is estimated by the relationship between viscosity and pressure drop, and the cathode pressure drop is quickly calculated to obtain the amount of each component through Dalton's law, achieving rapid convergence of parameters on the cathode closed circuit, which is beneficial to improving the cathode circuit parameters and the efficiency of the equipment under positive pressure flow.

[0037] The third aspect of the present invention provides a fuel cell design system, characterized in that it includes an anode module, a cathode module, and an equipment module; the anode module is used to obtain the anode loop nitrogen concentration according to any one of the anode loop nitrogen concentration design methods, and obtain the fuel cell system operating parameters obtained in the calculation step, including the anode outlet nitrogen volume N N2,aout , hydrogen volume at anode outlet N H2,aout , anode outlet water volume N H2O,aout , anode outlet pressure P aout , nitrogen gas volume at anode inlet N N2,ain , hydrogen volume at the anode inlet N H2,ain , anode inlet water volume N H2O,ain , anode inlet pressure P ain , total anode outlet N aout , anode outlet volume V aout , anode outlet pressure drop ΔPa, anode outlet water ratio f H2O , anode outlet hydrogen ratio fh, anode outlet nitrogen ratio fn; the cathode module is used to obtain the current cathode tolerance pressure drop according to any one of the cathode tolerance pressure drop design methods, and obtain the operating parameters obtained in the step, including the cathode inlet pressure P cin , Nitrogen volume at cathode inlet N N2,cin , Cathode outlet nitrogen volume N N2,cout , cathode outlet oxygen quantity N O2,cout , cathode inlet oxygen quantity N O2,cin , total cathode outlet volume V cout , cathode outlet pressure Pcout , cathode outlet water volume N H2O,cout , cathode inlet water partial pressure P H2O,cin , cathode inlet water volume N H2O,cin , cathode stack pressure drop ΔPc; the equipment module is used to obtain the equipment parameters of the fuel cell system according to any one of the cathode tolerance pressure drop design methods, including the humidifier wet end downstream pressure Pwo, the cathode outlet pipe pressure Pend, the cathode inlet dew point temperature T dp,cin .

[0038] In this way, on the one hand, the overall design of the system can meet the positive pressure flow of the fuel cell system pipelines, and the accurate calculation of the nitrogen concentration in the anode loop can be achieved to improve the efficiency of the stack. On the one hand, the calculation of the relevant operating parameters of the anode pipeline can be achieved in the nitrogen concentration calculation step, and the calculation of the relevant operating parameters of the cathode pipeline can be achieved in the cathode tolerance pressure drop calculation step. On the one hand, the operating parameters in the design can be integrated into the equipment parameter calculation, and the operating parameter designs of the cathode and anode can be linked together to achieve a global design of each pipeline and parameter of the fuel cell system, thereby improving the global efficiency of the system's stack, hydrogen cycle, and compression cycle.

[0039] As a preferred technical solution of the present invention, the anode module of the fuel cell design system is further used to determine other anode pipeline operating parameters based on the parameters calculated in the anode loop nitrogen concentration design method, the cathode module is further used to determine other cathode pipeline operating parameters based on the parameters calculated in the cathode tolerance pressure drop design method, and the equipment module is further used to determine other equipment parameters based on the parameters calculated in the anode loop nitrogen concentration design method. Specifically, the calculations of each module of the fuel cell design system are as follows:

[0040] Cathode module:

[0041] The amount of oxygen at the cathode inlet N is obtained from the electrochemical equation O2,cin =n*I / 4 / F*αc, where I is the stack current density, F is the Faraday coefficient, αc is the cathode reaction coefficient, and n is the number of cells;

[0042] By air ratio and The amount of nitrogen at the cathode inlet N N2,cin =0.79 / 0.21*N O2,cin ;

[0043] Depend on The humidifier temperature gradient T hum =a13*(N O2,cin +N N2,cin ), a13 is the humidification coefficient;

[0044] In this way, the dew point temperature is affected by the humidifier, and the cathode inlet dew point temperature T is obtained. dp,cin =Th+b1-T hum ;

[0045] Thus, the dew point temperature The water partial pressure P at the cathode inlet is obtained. H2O,cin =10^(a1-a2 / (a3+T dp,cin ));

[0046] Depend on The cathode inlet water volume N is obtained by Dalton's principle H2O,cin =P H2O,cin / (P cin -P H2O,cin )*(N O2,cin +N N2,cin ), P cin is the cathode inlet pressure;

[0047] At the same time, the humidity principle and The relative humidity RH at the cathode inlet is cin =P H2O,cin / P sat,cin , where the cathode inlet saturated vapor pressure P sat,cin =10^(a1-a2 / (a3+Tc+b1)), cooling path outlet temperature Th=Tc+ΔT, a1, a2, a3 are the empirical coefficients of saturated vapor pressure, Tc is the cooling path inlet temperature, b1 is the temperature gradient, ΔT is the cooling path temperature difference;

[0048] Depend on The total cathode inlet N cin =N O2,cin +N N2,cin +N H2O,cin ;

[0049] And the cathode inlet volume V cin =(N O2,cin +N N2,cin +N H2O,cin )*R*(Tc+b1) / P cin , R is the gas constant;

[0050] The amount of oxygen at the cathode outlet is the unreacted remainder, which is determined by Yes, N O2,cout =N O2,cin *(αc-1) / αc, and nitrogen does not participate in the reaction, then The amount of nitrogen at the cathode outlet is N N2,cout=N N2,cin ;

[0051] The cathode outlet water volume is estimated by the outlet pressure due to the lack of inlet pressure value. The estimated water volume at the cathode outlet is N H2O,cout,app =P sat,cout / (P cin -P sat,cout )*(N O2,cout +N N2,cout ), where the cathode outlet saturated vapor pressure P sat,cout =10^(a1-a2 / (a3+Th+b1));

[0052] Then use the pressure drop formula from and Calculate the cathode stack voltage drop ΔPc=((N O2,cout *θ O2,out +N N2,out *θ N2,out +N H2O,cout,app *θ H2O,out )*R*(Tc+b1) / P cin +(N O2,cin *θ O2,in +N N2,cin *θ N2,in +N H2O,cin *θ H2O,in )*R*(Th+b1) / P cin )*fc / n, fc is the cathode voltage drop coefficient, θ O2,out is the oxygen outlet viscosity, θ N2,out is the nitrogen outlet viscosity, θ H2O,out is the water vapor outlet viscosity, θ O2,in is the oxygen inlet viscosity, θ N2,in is the nitrogen inlet viscosity, θ H2O,in is the water vapor inlet viscosity;

[0053] Where, oxygen inlet viscosity θ O2,in =a4 / (Tc+b1+a5)*((Tc+b1) / a6)^1.5, a4, a5, a6 are the oxygen viscosity coefficients, and the oxygen outlet viscosity θ O2,out =a4 / (Th+b1+a5)*((Th+b1) / a6)^1.5, nitrogen inlet viscosity θ N2,in =a7 / (Tc+b1+a8)*((Tc+b1) / a9)^1.5, a7, a8, a9 are the nitrogen viscosity coefficients, and the nitrogen outlet viscosity θ N2,out =a7 / (Th+b1+a8)*((Th+b1) / a9)^1.5, water vapor inlet viscosity θ H2O,in=(a10+a11*(Tc+b1)-a12*(Tc+b1)^2), a10, a11, a12 are the water vapor viscosity coefficients, and the water vapor outlet viscosity θ H2O,out =(a10+a11*(Th+b1)-a12*(Th+b1)^2), hydrogen inlet viscosity θ H2,in =a18 / (Tc+b1+a19)*((Tc+b1) / a20)^1.5, a18, a19, a20 are hydrogen viscosity coefficients, hydrogen outlet viscosity θ H2,out =a18 / (Th+b1+a19)*((Th+b1) / a20)^1.5;

[0054] Depend on Calculate the cathode outlet pressure P cout =P cin -ΔPc;

[0055] According to the partial pressure law and The cathode outlet water volume N H2O,cout =P sat,cout / (P cout -P sat,cout )*(N O2,cout +N N2,cout );

[0056] The total cathode outlet volume V cout =(N O2,cout +N N2,cout +N H2O,cout )*R*(Th+b1) / P cout ;

[0057] By and The cathode net water ratio fw=(N H2O,cout -N H2O,cin ) / n / I*2F;

[0058] Among them, the total liquid water volume of the stack N liquid =N H2O,cin -N H2O,cout +I*n / 2 / F;

[0059] Anode module:

[0060] Considering the stack transmembrane pressure drop, the anode inlet pressure P ain =P cin +ΔP T , where ΔPT is the stack transmembrane pressure drop;

[0061] Anode inlet hydrogen volume N H2,ain =N H2,aout +n*I / 2 / F, hydrogen volume at anode outlet N H2,aout exist to obtain;

[0062] The anode inlet water volume remains unchanged N H2O,ain =N H2O,aout , the amount of nitrogen at the anode inlet remains unchanged N N2,ain =N N2,aout , where the anode outlet water volume N H2O,aout and the anode outlet nitrogen volume N N2,aout exist to obtain;

[0063] By The water partial pressure P at the anode inlet is obtained H2O,ain =N H2O,ain / (N H2O,ain +N N2,ain +N H2,ain )*P ain ;

[0064] The anode inlet humidity RH ain =P H2O,ain / P sat,ain , where the anode inlet saturated vapor pressure P sat,ain =10^(a1-a2 / (a3+Tc+b1));

[0065] The anode dew point temperature T dp,ain =-1730.63 / (lgP H2O,ain -10.19621)-233.462;

[0066] Since the anode is a circulating circuit, it is not convenient to solve it directly. First, the anode outlet pressure drop is required.

[0067] Depend on Estimate the anode outlet water ratio f H2O =P sat,aout / P ain , where the anode outlet saturated vapor pressure P sat,aout =10^(a1-a2 / (a3+Th+b1));

[0068] By The hydrogen ratio at the anode outlet is fh=1-fn*(1-f H2O )-f H2O , where fn is the nitrogen fraction at the anode outlet;

[0069] The anode outlet volume is given by the cycle formula and and Obtain:

[0070] V aout =(-(((θ H2,in +θ H2,out )*fh+(θ H2O,in +θ H2O,out )*f H2O +(θ N2,in +θ N2,out )*fn*(1-f H2O ))*ff / n)-((((θ H2,in +θ H2,out )*fh+(θ H2O,in +θ H2O,out )*f H2O +(θ N2,in +θ N2,out )*fn*(1-f H2O ))*ff / n)^2-4*(fh*b2+(1-fh)*b3)*(-I / 2 / F*R*(Tc+b1) / P ain *ff*θ H2,in +b4*((θ H2,in +θ H2,out )*fh+(θ H2O,in +θ H2O,out )*f H2O +(θ N2,in +θ N2,out )*fn*(1-f H2O ))*ff / n))^0.5) / 2 / (fh*b2+(1-fh)*b3)+b4, ff is the anode voltage drop coefficient, b2, b3, b4 are the cycle coefficients;

[0071] The anode outlet pressure drop is given by ΔPa=fh*(b5*(V aout -b4)^2–b6*(V aout -b4)+b7)+(1-fh)*(b8*(V aout -b4)^2–b9*(V aout -b4)+b10), b5, b6, b7, b8, b9, b10 are the boost coefficients;

[0072] Anode outlet pressure P aout =P ain -ΔPa;

[0073] The total amount of the anode outlet is given by the gas state equation: Find N aout =V aout *P aout / R / (Th+b1);

[0074] The amount of hydrogen at the anode outlet is N H2,aout =N aout *fh;

[0075] The amount of nitrogen at the anode outlet is N N2,aout =fn / (1-fn)*N H2,aout ;

[0076] The anode outlet water volume is determined by the partial pressure law and Calculate N H2O,aout =P sat,aout / P aout *(1-P sat,aout / P aout )*(N H2,aout +N N2,aout );

[0077] By and The anode hydrogen reaction coefficient αa=N H2,ain / (N H2,ain -N H2,aout );

[0078] The viscosity of the anode outlet gas is θ aout =(N H2,aout *θ H2,out +N N2,aout *θ N2,out +N H2O,aout *θ H2O,out ) / (N H2,aout +N N2,aout +N H2O,aout );

[0079] The nitrogen concentration in the anode circuit is then balanced by and Obtained, C N2 =(1-Fa)*N N2,aout / (N N2,aout +N H2,aout +N H2O,aout )*P aout / R / (Th+b1)+Fa*N N2,ain / (N H2,ain +N N2,ain +N H2O,ain)*P ain / R / (Tc+b1), Fa is the anode reflux ratio;

[0080] Step C N2 and target C N2,t If the difference is less than the threshold, the calculation ends. If it does not converge, update fn = C N2,t / C N2 *fn, restart from Start calculating.

[0081] Equipment module:

[0082] Calculation of cathode pipeline equipment parameters:

[0083] Depend on Calculate the pressure drop ΔP at the wet gas end of the humidifier 增湿w =k1*V cout , k1 is the humidifier pressure drop coefficient;

[0084] Depend on Calculate the pressure drop ΔP at the dry gas end of the humidifier 增湿d =k2*V cin , k2 is the humidifier pressure drop coefficient;

[0085] The downstream pressure of the wet gas end of the humidifier is So Pwo=P cout -ΔP 增湿w ;

[0086] The upstream pressure of the dry gas end of the humidifier is obtained from the inlet pressure Pdi=P cin +ΔP 增湿d ;

[0087] Depend on The cathode tube valve pressure drop ΔP 阀门 =(32*N O2,cin +28*N N2,cin )^2 / Pwo*k3, k3 is the valve pressure drop coefficient;

[0088] Depend on and Valve ρ0 is the air density, is the density at the upstream end of the valve;

[0089] Cathode outlet pipeline pressure drop ΔP 出口管 =(32*N O2,cin +28*N N2,cin )^2 / P0*k4, k4 is the pipeline pressure drop coefficient;

[0090] The pressure at the cathode outlet tube can be deduced from the ambient pressure to be Pend=P0+ΔP 出口管 ;

[0091] Depend on The intercooler pressure drop ΔP 中冷器 =(N O2,cin +N N2,cin )^2 / Pdi*k5, k5 is the intercooler pressure drop coefficient;

[0092] The compressor outlet pressure is P 压缩机出口 =Pdi+ΔP 中冷器 ;

[0093] Filter pressure drop ΔP 过滤 =(N O2,cin +N N2,cin )*R*T0 / P0*k6, k6 is the filter pressure drop coefficient;

[0094] The compressor inlet pressure P 压缩机进口 =P0-ΔP 过滤 ;

[0095] The compression ratio of the compressor is compr = P 压缩机出口 / P 压缩机进口 ;

[0096] Compressor compression flow V 压缩机 =(N O2,cin +N N2,cin )*R*T0 / P 压缩机进口 ;

[0097] Compressor compression efficiency η=(-a14*(V 压缩机 *compr)^2+a15*(V 压缩机 *compr)+a16) / 100, a14, a15, a16 compressor efficiency coefficient;

[0098] Compressor compression power W = (compr^((1.401-1) / 1.401)-1)*V 压缩机 *P 压缩机进口 *1.401 / (1.401-1) / η;

[0099] Stack power Wc = n*I*V, where V is the stack voltage;

[0100] The net output power of the stack is Wn = W-Wc;

[0101] Minimum cathode tube diameter Maximum diameter of cathode tube k7, k8 are pipeline flow velocity coefficients;

[0102] Calculation of anode pipeline equipment parameters:

[0103] The water distribution capacity of the water distributor is determined by Get N 分水器 =N liquid ;

[0104] Water distributor pressure drop ΔP 分水器 =N aout / P aout *k9, k9 is the water distributor pressure drop coefficient;

[0105] Then the pressure downstream of the water distributor is P 分水 =P aout -ΔP 分水器 ;

[0106] Minimum diameter of anode line

[0107] Maximum diameter of anode tube k7, k8 are pipeline flow velocity coefficients;

[0108] Anode outlet pipeline pressure drop ΔP 阳极管 =(2*N H2,aout +28*N N2,aout +18*N H2O,aout )^2 / P 分水 *k4, k4 is the pipeline pressure drop coefficient;

[0109] Ejector compression ratio compr2 = P ain / (P aout -ΔP 阳极管 -ΔP 分水器 ), ejector ratio RJ=N aout / (N H2,ain -N H2,aout );

[0110] Calculation of cooling pipeline equipment parameters:

[0111] Calculated from the power Heat of the stack main heat exchanger Q1 = ((1.25*fw+1.48*(1-fw))-V)*I*n;

[0112] The coolant flow rate of the main heat exchanger is given by the heat exchange equation N coolant1 =Q1 / (Th-Tc) / a17, where a17 is the heat capacity of the coolant;

[0113] Compressor intercooler heat The calculation of the compressor shows that Q2 = W*(1-η), so the flow rate of the coolant N coolant2 =Q2 / (Th-Tc) / a17;

[0114] The pressure drop of the cooling pipe is ΔP coolant =fk*(N coolant2 +N coolant1 )*(θ H2O,out +θ H2O,in ), fk is the cooling hydraulic pressure drop coefficient;

[0115] Then the required heat exchanger area of ​​the main heat exchanger is A1=Q1 / k10, k10 is the heat transfer coefficient of the heat exchanger,

[0116] The intercooler requires a heat exchange area of ​​A2 = Q2 / k10;

[0117] Depend on To calculate the difference ΔPerr = Pwo-ΔP 阀门 -Pend;

[0118] To determine convergence, if the ΔPerr change from the last time is less than the threshold, the calculation converges, if not, update P cin =P cin -ΔPerr, re- Start calculating.

[0119] In this way, by adopting the anode nitrogen concentration design method in the anode module of the fuel cell design system and the cathode tolerance pressure drop design method in the cathode module, the parameter designs of the cathode and anode paths are linked together, and the parameters obtained from the cathode and anode pipelines are used in the design of equipment parameters, while the operations of the cathode, anode and cooling paths and the influences between the equipment are integrated together, thereby achieving the overall design and optimization of the fuel cell system, while taking into account the efficiency of hydrogen recovery and utilization in the anode loop and the safety and electrical reaction efficiency of the positive pressure flow of gas in the cathode path, promoting the improvement of the overall efficiency of the system, and avoiding complex multivariate and multiple solution calculations, making the design calculations fast and simple.

[0120] Preferably, the fuel cell design system can calculate the current anode reflux ratio Fa=k21*compr2^k22 in the design, where k21, k22 are reflux ratio conversion coefficients; then determine the convergence, at the current Fa 当前 and History 历史 When the absolute value of the difference is less than the threshold, it is determined to be converged and the calculation ends. 当前 and History 历史 If the absolute value of the difference is greater than or equal to the threshold and the calculation does not converge, then update the cathode reaction coefficient αc=αc*Fa 当前 / Fa 历史 , repeat the anode recirculation ratio calculation. In this way, while ensuring the anode circulation efficiency, the anode circuit parameters can be linked to the cathode reaction coefficient of the cathode circuit to influence the design of relevant parameters of the cathode circuit, thereby affecting the electrochemical reaction efficiency and power of the fuel cell stack, and thus controlling the overall operating efficiency of the fuel cell system.

[0121] Compared with the prior art, the present invention has the following beneficial effects:

[0122] (1) The present invention uses a hydrogen circulation loop design at the anode of the fuel cell system, introduces the complex situation of nitrogen concentration accumulation in the calculation, and uses the anode parameters under the influence of the cathode parameters for calculation, so that the obtained anode loop nitrogen concentration is dynamically related to the system, and the nitrogen concentration is used to calculate the appropriate operating conditions and equipment parameters of the anode, which promotes the calculation of the anode path balance and circulation, simplifies the operating steps, and is conducive to optimizing the influence of the anode nitrogen concentration on the stack efficiency and residual hydrogen recovery.

[0123] (2) The present invention links the parameters of the anode circuit, cathode circuit, and cooling circuit together through the conservation of mass and thermodynamic relationships, and uses the parameters obtained from the design of the anode circuit nitrogen concentration and the cathode tolerance pressure drop to calculate the system equipment, thereby realizing the global optimization design of the fuel cell system. In this way, while taking into account the efficiency of the fuel cell stack, safe and reliable operation can be guaranteed. In addition, the parameter calculation is accurate, the design method is simple, the cost is low, and the design flexibility for different scenarios is high.

[0124] (3) In addition, the present invention combines the operating parameters of each pipeline in the fuel cell system with the equipment parameters, taking into account the equipment efficiency, stack efficiency, and thermodynamic efficiency, thereby achieving balanced optimization of the fuel cell system between the equipment operating conditions.

[0125] (4) In the cathode tolerance pressure drop design, the cathode inlet pressure P is determined by pressure drop transfer. cin This ensures that the design of operations and equipment such as the cathode and anode circuits can meet the positive pressure gas flow in the cathode pipeline, and also avoids the problem of excessive humidity design leading to battery flooding due to ignoring the influence of equipment on air pressure in ordinary methods, thereby ensuring the overall safety of equipment design.

Claims

1. A method for designing nitrogen concentration in an anode circuit, characterized in that: include: S1. According to the physical quantity of the cathode pipeline, the partial pressure law and the law of conservation of materials are used to determine the nitrogen volume N at the anode outlet. N2,aout , hydrogen volume at anode outlet N H2,aout , anode outlet water volume N H2O,aout , anode outlet pressure P aout , nitrogen gas volume at anode inlet N N2,ain , hydrogen volume at the anode inlet N H2,ain , anode inlet water volume N H2O,ain , anode inlet pressure P ain ; S2. Calculate the nitrogen concentration C in the anode circuit based on the flow rate, pressure, temperature of each component of the anode and cathode, as well as the anode return ratio. N2 =(1-Fa)*N N2,aout / (N N2,aout +N H2,aout +N H2O,aout )*P aout / R / (Th+b1)+Fa*N N2,ain / (N H2,ain +N N2,ain +N H2O,ain )*P ain / R / (Tc+b1); where N N2,aout is the nitrogen volume at the anode outlet, N H2,aout is the amount of hydrogen at the anode outlet, N H2O,aout is the anode outlet water volume, P aout is the anode outlet pressure, R is the gas constant, Th is the cooling path outlet temperature Th=Tc+ΔT, Tc is the cooling path inlet temperature, b1 is the temperature gradient, N N2,ain is the nitrogen volume at the anode inlet, N H2,ain is the amount of hydrogen at the anode inlet, N H2O,ain is the anode inlet water volume, P ain is the anode inlet pressure, Fa is the anode recirculation ratio, and ΔT is the cooling path temperature difference.

2. The anode circuit nitrogen concentration design method according to claim 1, characterized in that: The step S1 comprises: S1.

1. Calculate the anode inlet pressure P according to the cathode inlet pressure and the stack transmembrane pressure drop. ain =P cin +ΔPT, where P cin is the cathode inlet pressure, ΔPT is the stack transmembrane pressure drop, P ain Anode inlet pressure; S1.

2. Calculate the anode outlet water ratio f based on the anode inlet pressure, viscosity of each component, anode outlet nitrogen ratio, and temperature. H2O =P sat,aout / P ain , anode outlet hydrogen ratio fh=1-fn*(1-f H2O )-f H2O , anode outlet volume V aout =(-(((θ H2,in +θ H2,out )*fh+(θ H2O,in +θ H2O,out )*f H2O +(θ N2,in +θ N2,out )*fn*(1-f H2O ))*ff / n)-((((θ H2,in +θ H2,out )*fh+(θ H2O,in +θ H2O,out )*f H2O +(θ N2,in +θ N2,out )*fn*(1-f H2O ))*ff / n)^2-4*(fh*b2+(1-fh)*b3)*(-I / 2 / F*R*(Tc+b1) / P ain *ff*θ H2,in +b4*((θ H2,in +θ H2,out )*fh+(θ H2O,in +θ H2O,out )*f H2O +(θ N2,in +θ N2,out )*fn*(1-f H2O ))*ff / n))^0.5) / 2 / (fh*b2+(1-fh)*b3)+b4, anode outlet pressure drop ΔPa=fh*(b5*(V aout -b4)^2–b6*(V aout -b4)+b7)+(1-fh)*(b8*(V aout -b4)^2–b9*(V aout -b4)+b10), and anode outlet pressure P aout =P ain -ΔPa, where P sat,aout is the saturated vapor pressure at the anode outlet P sat,aout =10^(a1-a2 / (a3+Th+b1)), P ain is the anode inlet pressure, ΔPa is the anode outlet pressure drop, fn is the anode outlet nitrogen ratio, f H2O Anode outlet water ratio, fh anode outlet hydrogen ratio, V aout is the anode outlet volume, θ H2,in is the hydrogen inlet viscosity, θ H2,out is the hydrogen outlet viscosity, θ H2O,in is the water vapor inlet viscosity, θ H2O,out is the water vapor outlet viscosity, θ N2,in is the nitrogen inlet viscosity, θ N2,out is the nitrogen outlet viscosity, n is the number of cells, I is the current density, R is the gas constant, F is the Faraday coefficient, Tc is the cooling path inlet temperature, ff is the anode pressure drop coefficient, b1 is the temperature gradient, b2, b3, b4 are the cycle coefficients, b5, b6, b7, b8, b9, b10 are the pressurization coefficients, a1, a2, a3 are the empirical coefficients of saturated vapor pressure; S1.

3. Calculate the anode outlet hydrogen volume N based on the anode outlet total volume and the anode outlet hydrogen ratio. H2,aout =N aout *fh, and the amount of hydrogen at the anode inlet N H2,ain =N H2,aout +n*I / 2 / F, where N aout is the total amount of anode outlet, fh is the hydrogen ratio of anode outlet, F is the Faraday coefficient, I is the stack current density, n is the number of cells, N H2,aout Anode outlet hydrogen volume, N H2,ain Anode inlet hydrogen volume; S1.

4. Calculate the nitrogen volume N at the anode outlet based on the ratio of hydrogen volume to nitrogen volume at the anode outlet. N2,aout = nitrogen gas volume at anode inlet N N2,ain =fn / (1-fn)*N H2,aout , where fn is the nitrogen ratio at the anode outlet, N N2,aout Anode outlet nitrogen volume, N N2,ain Anode inlet nitrogen volume; S1.

5. Calculate the anode outlet water volume N based on the anode outlet pressure, saturated vapor pressure, anode outlet hydrogen volume and nitrogen volume. H2O,aout = anode inlet water volume N H2O,ain =P sat,aout / P aout *(1-P sat,aout / P aout )*(N H2,aout +N N2,aout ), where P sat,aout is the saturated vapor pressure at the anode outlet, N H2,aout Anode outlet hydrogen volume, N N2,aout Anode outlet nitrogen volume, P aout Anode outlet pressure, N H2O,aout Anode outlet water volume.

3. The method for designing nitrogen concentration in the anode circuit according to claim 2, wherein: The total amount of anode outlet N in step S1.3 aout =V aout *P aout / R / (Th+b1), where Th is the cooling outlet temperature, b1 is the temperature gradient, R is the gas constant, V aout Anode outlet volume, P aout Anode outlet pressure.

4. The method for designing nitrogen concentration in the anode circuit according to claim 1 or 2, characterized in that: The step S2 calculates the nitrogen concentration C in the anode circuit. N2,ave Then calculate C N2 and target nitrogen concentration C N2,t The difference between |C N2 -C N2,t |, when |C N2 -C N2,t | is less than the threshold, it is judged to be converged and the calculation ends. N2 -C N2,t | is greater than or equal to the threshold, it is judged as non-convergence, and the nitrogen ratio at the anode outlet is updated fn=C N2,t / C N2 *fn, repeated calculation of the anode circuit nitrogen concentration.

5. A fuel cell design system, characterized in that: The invention comprises an anode module, a cathode module and an equipment module; the anode module is used to obtain the anode loop nitrogen concentration according to the anode loop nitrogen concentration design method according to any one of claims 1 to 4, and obtain the fuel cell system operating parameters obtained in the calculation step, including the anode outlet nitrogen volume N N2,aout , hydrogen volume at anode outlet N H2,aout , anode outlet water volume N H2O,aout , anode outlet pressure P aout , nitrogen gas volume at anode inlet N N2,ain , hydrogen volume at the anode inlet N H2,ain , anode inlet water volume N H2O,ain , anode inlet pressure P ain , total anode outlet N aout , anode outlet volume V aout , anode outlet pressure drop ΔPa, anode outlet water ratio f H2O , hydrogen ratio at anode outlet fh, nitrogen ratio at anode outlet fn; The cathode module is used to obtain the current cathode tolerance pressure drop according to the cathode tolerance pressure drop design method, and obtain the operating parameters obtained in the step, including the cathode inlet pressure P cin , Nitrogen volume at cathode inlet N N2,cin , Cathode outlet nitrogen volume N N2,cout , cathode outlet oxygen quantity N O2,cout , cathode inlet oxygen quantity N O2,cin , total cathode outlet volume V cout , cathode outlet pressure P cout , cathode outlet water volume N H2O,cout , cathode inlet water partial pressure P H2O,cin , cathode inlet water volume N H2O,cin , cathode stack pressure drop ΔPc; the equipment module is used to obtain the equipment parameters of the fuel cell system according to the cathode tolerance pressure drop design method, including the downstream pressure Pwo of the humidifier wet gas end, the pressure Pend at the cathode outlet pipe, and the cathode inlet dew point temperature T dp,cin .

6. The fuel cell design system according to claim 5, characterized in that: The cathode tolerance voltage drop design method includes: T1. Calculate the amount of nitrogen N at the cathode inlet based on the input parameters N2,cin , the amount of oxygen at the cathode inlet N O2,cin , total cathode outlet volume V cout , cathode outlet pressure P cout ; T2. Calculate the pressure drop ΔP at the wet gas end of the humidifier 增湿w =k1*V cout , humidifier wet end downstream pressure Pwo=P cout -ΔP 增湿w , cathode tube valve pressure drop ΔP 阀门 =(32*N O2,cin +28*N N2,cin )^2 / Pwo*k3, cathode outlet pipe pressure drop ΔP 出口管 =(32*N O2,cin +28*N N2,cin )^2 / P0*k4, and the pressure at the cathode outlet pipe Pend=P0+ΔP 出口管 , where ΔP 增湿w is the pressure drop at the wet gas end, k1 is the humidifier pressure drop coefficient, k3 is the valve pressure drop coefficient, k4 is the pipeline pressure drop coefficient, and P0 is the ambient pressure; T3. Calculate the current cathode tolerance voltage drop ΔPerr=Pwo-ΔP 阀门 -Pend, to determine convergence, at the current ΔPerr 当前 and historical ΔPerr 历史 When the absolute value of the difference is less than the threshold, the calculation converges and ends. 当前 and historical ΔPerr 历史 If the absolute value of the difference is greater than or equal to the threshold and the calculation does not converge, update P cin =P cin -ΔPerr 当前 , repeat the cathode tolerance voltage drop calculation.

7. The fuel cell design system according to claim 6, characterized in that: The step T1 includes: T1.1, calculating the amount of oxygen N at the cathode inlet O2,cin =n*I / 4 / F*αc, the amount of oxygen at the cathode outlet N O2,cout =N O2,cin *(αc-1) / αc, where I is the stack current density, F is the Faraday coefficient, and αc is the cathode reaction coefficient; T1.

2. Calculate the amount of nitrogen at the cathode inlet N N2,cin = Nitrogen volume at cathode outlet N N2,cout =0.79 / 0.21*N O2,cin ; T1.3, calculate the humidifier temperature gradient T hum =a13*(N O2,cin +N N2,cin ), cathode inlet dew point temperature T dp,cin =Th+b1-T hum , cathode inlet water partial pressure P H2O,cin =10^(a1-a2 / (a3+T dp,cin )), cathode inlet water volume N H2O,cin =P H2O,cin / (P cin -P H2O,cin )*(N O2,cin +N N2,cin ), estimated water volume at cathode outlet N H2O,cout,app =P sat,cout / (P cin -P sat,cout )*(N O2,cout +N N2,cout ), and cathode stack voltage drop ΔPc=((N O2,cout *θ O2,out +N N2,out *θ N2,out +N H2O,cout,app *θ H2O,out )*R*(Tc+b1) / P cin +(N O2,cin *θ O2,in +N N2,cin *θ N2,in +N H2O,cin *θ H2O,in )*R*(Th+b1) / P cin )*fc / n, where the cathode outlet saturated vapor pressure P sat,cout =10^(a1-a2 / (a3+Th+b1)), b1 is the temperature gradient, Th is the cooling path outlet temperature, Tc is the cooling path inlet temperature, a1, a2, a3 are the empirical coefficients of saturated vapor pressure, R is the gas constant, a13 is the humidification coefficient, P cin Cathode inlet pressure, θ O2,out is the oxygen outlet viscosity, θ N2,out is the nitrogen outlet viscosity, θ H2O,out is the water vapor outlet viscosity, θ O2,in is the oxygen inlet viscosity, θ N2,in is the nitrogen inlet viscosity, θ H2O,in is the water vapor inlet viscosity, fc is the cathode voltage drop coefficient, and n is the number of cells; T1.

4. Calculate cathode outlet pressure P cout =P cin -ΔPc, and cathode outlet water volume N H2O,cout =P sat,cout / (P cout -P sat,cout )*(N O2,cout +N N2,cout ); T1.

5. Calculate the total cathode outlet volume V cout =(N O2,cout +N N2,cout +N H2O,cout )*R*(Th+b1) / P cout .

8. The fuel cell design system according to claim 5, characterized in that: The anode module of the fuel cell design system is further used to determine other anode pipeline operating parameters based on the operating parameters obtained in claim 6; the design of the other anode pipeline operating parameters includes: (A1) Anode inlet water partial pressure P H2O,ain =N H2O,ain / (N H2O,ain +N N2,ain +N H2,ain )*P ain ; (A2) Anode inlet humidity RH ain =P H2O,ain / P sat,ain , where the anode inlet saturated vapor pressure P sat,ain =10^(a1-a2 / (a3+Tc+b1)), where a1, a2, and a3 are the empirical coefficients of saturated vapor pressure, Tc is the cooling path inlet temperature, and b1 is the temperature gradient; (A3) Anode dew point temperature T dp,ain =-1730.63 / (lgP H2O,ain -10.19621)-233.462; (A4) Anode hydrogen reaction coefficient αa=N H2,ain / (N H2,ain -N H2,aout ); (A5) The viscosity of the gas at the anode outlet is θ aout =(N H2,aout *θ H2,out +N N2,aout *θ N2,out +N H2O,aout *θ H2O,out ) / (N H2,aout +N N2,aout +N H2O,aout ).

9. The fuel cell design system according to claim 8, characterized in that: The cathode module of the fuel cell design system is further used to obtain other cathode pipeline operating parameters based on the operating parameters obtained in claim 6; the design of the other cathode pipeline operating parameters includes: (B1) Cathode inlet relative humidity RH cin =P H2O,cin / P sat,cin , where the cathode inlet saturated vapor pressure P sat,cin =10^(a1-a2 / (a3+Tc+b1)), where a1, a2, and a3 are the empirical coefficients of saturated vapor pressure, Tc is the cooling path inlet temperature, and b1 is the temperature gradient; (B2) cathode inlet total volume N cin =N O2,cin +N N2,cin +N H2O,cin ; (B3) Cathode inlet volume V cin =(N O2,cin +N N2,cin +N H2O,cin )*R*(Tc+b1) / P cin ; (B4) cathode net water ratio fw=(N H2O,cout -N H2O,cin ) / n / I*2F; (B5) Total liquid water volume N liquid =N H2O,cin -N H2O,cout +I*n / 2 / F, where I is the stack current density, n is the number of cells, and F is the Faraday coefficient.

10. The fuel cell design system according to claim 9, wherein: The equipment module of the fuel cell design system is further used to obtain other equipment parameters based on the operating parameters and equipment parameters obtained in claim 6; The other equipment parameter designs include: (C1) Cathode circuit equipment parameters: Humidifier dry gas end pressure drop ΔP 增湿d =k2*V cin , k2 is the humidifier pressure drop coefficient; Humidifier dry gas end upstream pressure Pdi=P cin +ΔP 增湿d ; ρ0 is the air density, is the density at the upstream end of the valve, Pwo is the pressure at the downstream end of the wet gas container; Intercooler pressure drop ΔP 中冷器 =(N O2,cin +N N2,cin )^2 / Pdi*k5, k5 is the intercooler pressure drop coefficient; Filter pressure drop ΔP 过滤 =(N O2,cin +N N2,cin )*R*T0 / P0*k6, k6 is the filter pressure drop coefficient, where T0 is the ambient temperature and P0 is the ambient pressure; The compressor inlet pressure is P 压缩机进口 =P0-ΔP 过滤 ; The compressor outlet pressure is P 压缩机出口 =Pdi+ΔP 中冷器 ; The compression ratio of the compressor is compr = P 压缩机出口 / P 压缩机进口 ; Compressor compression flow V 压缩机 =(N O2,cin +N N2,cin )*R*T0 / P 压缩机进口 ; Compressor compression efficiency η=(-a14*(V 压缩机 *compr)^2+a15*(V 压缩机 *compr)+a16) / 100, a14, a15, a16 compressor efficiency coefficient; Compressor compression power W = (compr^((1.401-1) / 1.401)-1)*V 压缩机 *P 压缩机进口 *1.401 / (1.401-1) / η; Stack power Wc = n*I*V, where V is the stack voltage; The net output power of the stack is Wn = W-Wc; Minimum cathode tube diameter Maximum diameter of cathode tube k7, k8 are pipeline flow velocity coefficients; (C2) Anode circuit equipment parameters: Water separation capacity of water distributor N 分水器 =N liquid ; Water distributor pressure drop ΔP 分水器 =N aout / P aout *k9, k9 is the water distributor pressure drop coefficient; Pressure P downstream of the water distributor 分水 =P aout -ΔP 分水器 ; The minimum diameter of the anode circuit is Maximum diameter of anode tube Among them, k7 and k8 are pipeline velocity coefficients; Anode outlet pipeline pressure drop ΔP 阳极管 =(2*N H2,aout +28*N N2,aout +18*N H2O,aout )^2 / P 分水 *k4, k4 is the pipeline pressure drop coefficient; Ejector compression ratio compr2 = P ain / (P aout -ΔP 阳极管 -ΔP 分水器 ); Ejector ejection ratio RJ=N aout / (N H2,ain -N H2,aout ); (C3) Cooling circuit equipment parameters: Main heat exchanger heat Q1 = ((1.25*fw+1.48*(1-fw))-V)*I*n, V is the stack voltage; Coolant flow rate of main heat exchanger N coolant1 =Q1 / (Th-Tc) / a17, where a17 is the heat capacity of the coolant; The required heat exchanger area of ​​the main heat exchanger is A1=Q1 / k10, where k10 is the heat transfer coefficient of the heat exchanger; Intercooler heat Q2 = W*(1-η); Intercooler coolant flow rate N coolant2 =Q2 / (Th-Tc) / a17; The intercooler requires a heat exchange area of ​​A2 = Q2 / k10; Cooling pipe pressure drop ΔP coolant =fk*(N coolant2 +N coolant1 )*(θ H2O,out +θ H2O,in ), fk is the cooling hydraulic pressure drop coefficient.

11. The fuel cell design system according to claim 10, wherein: Calculate the current anode reflux ratio Fa=k21*compr2^k22, where k21, k22 are reflux ratio conversion coefficients; to determine convergence, at the current Fa 当前 and historical 历史 When the absolute value of the difference is less than the threshold, it is determined to be converged and the calculation ends. 当前 and historical 历史 If the absolute value of the difference is greater than or equal to the threshold and the calculation does not converge, then update the cathode reaction coefficient αc=αc*Fa 当前 / Fa 历史 , repeat the anode reflux ratio calculation.

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