CN101067646A - A method for quickly evaluating the service life of vehicle fuel cells - Google Patents

Abstract

The invention relates to a method to fast appraise vehicle fuel battery service life, which includes the following step: 1.definie the fuel cell performance drops how much to the life end; 2. carry on fuel cell gantry experiment, definite fuel cell performance descending rate along with loading times, descending rate along with start and stop times, descending rate along with idle rate time; 3. carry on the statistics of the fuel cell situation in actual use process, the states statistical content includes the average each hour large scale loading times, average each hour starts and stops times and average each hour idle rate times; 4. carry on the computation of the 1-3 step results according to the invention method formula. The invention method reflected the influence each kind of key influence factor on the fuel cell life in the use process, can obtain the fuel cell usable life in the shorter run time within 150 hours.

Description

The method in a kind of fast estimating vehicle fuel battery serviceable life

Technical field

What the present invention relates to is a kind of estimating fuel battery method in serviceable life, particularly about a kind of fast estimating vehicle fuel battery method in serviceable life.

Background technology

The evaluation method in fuel cell serviceable life, generally can test (as Lifetime behavior of a PEM fuel cell with low humidification offeed stream by the operation of long-time continuous steady state condition, PHYSICAL CHEMISTRY CHEMICAL PHYSICS 7 (2): 373-378,2005), or combine by long-time continuous steady-state operation and intermitten service and to test, as 500 hours continuously operation add intermitten service in 50 hours (Degradation study on MEA in H₃PO₄/ PBI high-temperaturePEMFC life test, Journal of the Electrochemical Society vol.154 (1): B72-6,2007), the method that can also adopt repeatedly the operation of variable load dynamic operation condition to test, as voltage from 1.2V to 0.8V repeatedly varying duty (see PtCo/C cathode catalyst for improved durability in PEMFCs, J POWER SOURCES 144 (1): 11-20,2005).Steady state condition moves the method for testing continuously, and the time grows up to this height; The method of testing of variable load dynamic operation condition operation can be estimated out the comparative lifetime of fuel cell with the short time repeatedly, but determines the actual life of fuel cell than difficulty.A kind of method by variable load repeatedly and start-stop test is being studied by U.S. Ford Motor Company, attempted with 300 hours examination time equivalent actual 5500 hours serviceable life, but the result of report research also.

Summary of the invention

At the problems referred to above, the purpose of this invention is to provide a kind of fast estimating vehicle fuel battery method in serviceable life, this method can be estimated out the probable life of fuel cell at short notice.

For achieving the above object, the present invention takes following technical scheme: the method in a kind of fast estimating vehicle fuel battery serviceable life, and it is characterized in that: it may further comprise the steps: (1) definition fuel battery performance descends, and what are life termination; (2) carry out the fuel cell platform experiment, the speed that loads with actual under the identical condition of the operating position on the automobile, determine that described fuel battery performance is with the rate of descent of loading number of times, with the rate of descent of start-stop number of times, with the rate of descent of dead time; (3) described fuel cell situation is in actual use added up, the content of described statistics comprises and on average per hour loads number of times, on average per hour start-stop number of times and on average dead time per hour significantly; (4), obtain the probable life L of vehicle fuel battery with the following formula of substitution as a result in step (1)～(3)_f:

$L_f=k\·\frac{\mathrm{\ΔP}}{\frac{{\mathrm{\ΔP}}_1}{n_1}{N}_1+\frac{{\mathrm{\ΔP}}_2}{n_2}{N}_2+\frac{{\mathrm{\ΔP}}_3}{t}T}$

Described fuel cell performance is meant the peak power (W/cm of average monolithic battery²).

The present invention is owing to take above technical scheme, it has the following advantages: evaluation method of the present invention is owing to the Forecasting Methodology that is based on the fuel battery part experimental evaluation basis, it has reflected the influence of in use various key influence factors to fuel battery service life, so can be to obtain the probable life of fuel cell within 150 hours with short experimental period.

Embodiment

Below by embodiment the inventive method is described in detail.

The inventive method is based on the Forecasting Methodology on the fuel battery part experimental evaluation basis, and its concrete operations step is as follows:

(1) at first defines fuel battery performance and descend how much be life termination.Present embodiment the monolithic battery peak power from 0.6W/cm²Drop to 0.4W/cm²Be defined as life termination, Δ P=0.2W/cm²

(2) carry out the fuel cell platform experiment then, determine that fuel battery performance is with the rate of descent that loads number of times, with the rate of descent of start-stop number of times, with the rate of descent of dead time.The fuel cell pack platform experiment that present embodiment carries out, the test result that obtains is: 3000 loading experiments, loading amplitude are from being reduced to below the 0.6V average monolithic battery peak power reduction 0.001W/cm more than the 0.9V from average monolithic battery voltage²300 start-stops experiment, the monolithic battery peak power reduces 0.001W/cm²Idling experiment in 30 hours, average monolithic battery peak power reduces 0.001W/cm²

(3) fuel cell situation is in actual use added up, the content of statistics comprises and on average per hour loads number of times, on average per hour start-stop number of times and on average dead time per hour significantly again.Present embodiment is added up fuel cell situation in actual use, the statistical average result who obtains is: fuel cell on average per hour loads (voltage drops to below the 0.6V from 0.9V) 60 times/h significantly, on average per hour start-stop 3 times, on average idling 0.3 hour per hour.

(4) result in the above steps is calculated as follows:

$L_f=k\·\frac{\mathrm{\ΔP}}{\frac{{\mathrm{\ΔP}}_1}{n_1}{N}_1+\frac{{\mathrm{\ΔP}}_2}{n_2}{N}_2+\frac{{\mathrm{\ΔP}}_3}{t}T}$

Wherein, L_fIt is the probable life of vehicle fuel battery;

Δ P is average monolithic fuel cell maximum power permission reduction value;

Be n₁Inferior start-stop empirical average monolithic fuel cell maximum power reduces Δ P₁

Be n₂Inferior start-stop empirical average monolithic fuel cell maximum power reduces Δ P₂

Be that t hour idling empirical average monolithic fuel cell maximum power reduces Δ P₃

N₁On average per hour load number of times when being actual use significantly;

N₂Average start-stop number of times per hour when being actual use;

Shared time of idling per hour when T is actual use;

K is a correction factor, and k≤1;

When using this formula for the first time, getting correction factor is 1.After treating the fuel battery service life result of actual motion, the correction factor in the computing formula is made amendment, to improve prediction accuracy.

Present embodiment calculates through formula, and the probable life of prediction of result fuel cell is 5000 hours.

Adopt the result in the inventive method predict fuel battery serviceable life to compare with existing test evaluation fuel lifetime result, the inventive method has reflected the influence of in use various key influence factors to fuel battery service life, can obtain the probable life of fuel cell with experimental period short within 150 hours.

Claims (2)

Translated fromChinese

1、一种快速评价车用燃料电池使用寿命的方法，其特征在于：它包括以下步骤：1. A method for rapidly evaluating the service life of a fuel cell for vehicles, characterized in that: it may further comprise the steps:(1)定义燃料电池性能下降多少为寿命终结；(1) Define how much the performance of the fuel cell degrades as the end of life;(2)进行燃料电池台架实验，在加载的速度与实际在汽车上的使用情况相同的条件下，确定所述燃料电池性能随加载次数的下降率、随起停次数的下降率、随怠速时间的下降率；(2) Carry out the fuel cell bench test, under the condition that the speed of loading is the same as the actual usage on the automobile, determine the decline rate of the fuel cell performance with the number of times of loading, the rate of decline with the number of times of starting and stopping, and the rate of decline with the number of times of idle speed. rate of decline over time;(3)对所述燃料电池在实际使用过程中的情况进行统计，所述统计的内容包括平均每小时大幅度加载次数、平均每小时起停次数和平均每小时怠速时间；(3) Perform statistics on the situation of the fuel cell during actual use, the content of the statistics includes the average number of times of large-scale loading per hour, the average number of times of starting and stopping per hour, and the average time of idling per hour;(4)将步骤(1)～(3)中的结果代入以下公式，得到车用燃料电池的可用寿命L_f：(4) Substitute the results in steps (1) to (3) into the following formula to obtain the usable life L_f of the vehicle fuel cell:${\mathrm{<span><span>L</span>L</span>}}_{\mathrm{<span><span>f</span>f</span>}}<span><span>=</span>=</span>\mathrm{<span><span>k</span>k</span>}<span><span>\&CenterDot;</span>\&Center\; Dot;</span>\frac{\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}}{\frac{\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>1</span>1</span>}}}{{\mathrm{<span><span>n</span>no</span>}}_{\mathrm{<span><span>1</span>1</span>}}}{\mathrm{<span><span>N</span>N</span>}}_{\mathrm{<span><span>1</span>1</span>}}<span><span>+</span>+</span>\frac{\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>2</span>2</span>}}}{{\mathrm{<span><span>n</span>no</span>}}_{\mathrm{<span><span>2</span>2</span>}}}{\mathrm{<span><span>N</span>N</span>}}_{\mathrm{<span><span>2</span>2</span>}}<span><span>+</span>+</span>\frac{\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>3</span>3</span>}}}{\mathrm{<span><span>t</span>t</span>}}\mathrm{<span><span>T</span>T</span>}}$其中，ΔP是平均单片燃料电池最大功率许可降低值；Among them, ΔP is the allowable reduction value of the maximum power of the average single fuel cell;是n₁次加载实验平均单片燃料电池最大功率降低ΔP₁； is the average single-chip fuel cell maximum power reduction ΔP₁ for n₁ loading experiments;是n₂次起停实验平均单片燃料电池最大功率降低ΔP₂； is the average single fuel cell maximum power reduction ΔP₂ for n₂ start-stop experiments;

是t小时怠速实验平均单片燃料电池最大功率降低ΔP₃；

is the average single-chip fuel cell maximum power reduction ΔP₃ in the idling experiment for t hours;N₁是实际使用时平均每小时大幅度加载次数；N₁ is the average number of large loads per hour in actual use;N₂是实际使用时平均每小时起停次数；N₂ is the average number of starts and stops per hour in actual use;T是实际使用时每小时怠速所占时间；T is the time occupied by idle speed per hour in actual use;k是修正系数，且k≤1。k is a correction coefficient, and k≤1.2、如权利要求1所述的一种快速评价车用燃料电池使用寿命的方法，其特征在于：所述燃料电池的性能是指平均单片电池的最大功率(W/cm²)。2. A method for quickly evaluating the service life of a vehicle fuel cell according to claim 1, wherein the performance of the fuel cell refers to the maximum power (W/cm² ) of an average single-chip battery.