Co-reporter:Yongfeng Liu;Xiaoshe Jia
Chinese Journal of Mechanical Engineering 2016 Volume 29( Issue 1) pp:188-194
Publication Date(Web):2016 January
DOI:10.3901/CJME.2015.1116.134
For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation (EGR) rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80–437.40 g is imported into the device and last 1–20 min, respectively, 21.50–701.30 g dry ice is obtained. This research proposes a new design method which can capture CO2 for vehicular internal combustion engine.
Co-reporter:Hongfei Zhang, Pucheng Pei, Pengcheng Li, Xing Yuan
International Journal of Hydrogen Energy 2010 Volume 35(Issue 17) pp:9124-9133
Publication Date(Web):September 2010
DOI:10.1016/j.ijhydene.2010.05.121
Co-reporter:Pucheng Pei, Qianfei Chang, Tian Tang
International Journal of Hydrogen Energy 2008 Volume 33(Issue 14) pp:3829-3836
Publication Date(Web):July 2008
DOI:10.1016/j.ijhydene.2008.04.048
Fuel cell vehicle commercialization and mass production are challenged by the durability of fuel cells and could be promoted by accelerated lifetime evaluating methods. In this paper, an arithmetic equation of fuel cell lifetime is presented, which is relating with load changing cycles, start–stop cycles, idling time, high power load condition and the air pollution factor. Basing on the practical data gathered from a fuel cell bus and the test results of a fuel cell stack in laboratory, the calculated lifetime fits the bus real running lifetime very well. It is shown that the automotive fuel cell lifetime mightily depends on driving cycles, and the potential lifetime in different operating mode can be effectively predicted by using this method with about 300 h test time. The test results also show that the effect of start–stop cycling on fuel cell lifetime can be almost ignored if the stack open circuit voltage is dispelled quickly after fuel cell stops operating. It is worthwhile that from this quick lifetime-evaluating method we can find many possible directions to improve fuel cell durability.
Co-reporter:Pucheng Pei, Minggao Ouyang, Wei Feng, Languang Lu, Haiyan Huang, Jinhui Zhang
International Journal of Hydrogen Energy 2006 Volume 31(Issue 3) pp:371-377
Publication Date(Web):March 2006
DOI:10.1016/j.ijhydene.2005.08.008
Research on hydrogen pressure characteristics was performed for a fuel cell stack to supply a rule of hydrogen pressure drop for flooding diagnostic systems. Some experiments on the hydrogen pressure drop in various operating pressure, temperature, flowrate and stack current conditions were carried out, and hydrodynamic calculation was managed to compare with the experiment results. Results show that the hydrogen pressure drop is strongly affected by liquid water content in the flow channel of fuel cells, and it is not in normal relation with flowrate when the stoichiometric ratio is inconstant. The total pressure drop can be calculated by a frictional pressure loss formula accurately, relating with mixture viscosity, stack temperature, operating pressure, stoichiometric ratio and stack current. The pressure drop characteristics will be useful for predicting liquid water flooding in fuel cell stacks before flow channels have been jammed as a diagnostic tool in electric control systems.
Co-reporter:Pucheng Pei, Wu Yang, Ping Li
International Journal of Hydrogen Energy 2006 Volume 31(Issue 3) pp:361-369
Publication Date(Web):March 2006
DOI:10.1016/j.ijhydene.2005.06.028
Mathematical models were applied to predict the results of different strategies to improve automotive fuel cell driving systems. First, a fuel cell system was optimized on the base of a fuel cell stack model. Then calculations about the utilization of recovered energy from air exhaust steam were carried out. Two methods to combine the turbocharger with an electric compressor, namely in series and in parallel, were evaluated for a fuel cell system. Finally, research on the effect of removing the big power DC/DC converter, which is located between the fuel cell system and the driving motor, was conducted for a fuel cell driving system. The main results show that it is highly advantageous to connect the turbocharger with an electric compressor in series than in parallel; and that the fuel cell driving system without DC/DC converter before its motor could reach much higher performance characteristics, and even be so in lower power range while the cell voltage was designated to be lower.
Co-reporter:Yongfeng Liu, Pucheng Pei
International Journal of Hydrogen Energy 2006 Volume 31(Issue 5) pp:639-647
Publication Date(Web):April 2006
DOI:10.1016/j.ijhydene.2005.05.005
The deducted equations about chemical species and temperature are presented to calculate hydrogen–oxygen ignition delay time. Steady-state assumptions for many of the intermediate species are introduced to derive a new simplified 3-step mechanism. The simplified 3-step mechanism for hydrogen–oxygen leads the steady-state assumptions to linear differential equations. The competition among the full mechanism containing 17-, 8- and the simplified 3-step mechanisms is carried out. The resulting closed form solutions describe the low-, the intermediate- and the high-temperature ignition regimes and obtain an “S-shaped curve”. Finally, the two parameters on ignition and extinction of the continuously stirred flow reactor are discussed in detail and the temperature error analysis is given. It reduces the computational costs and supplies theory and methods for understanding autoignition and explosion limits of hydrogen–oxygen mixtures in homogeneous systems.
Co-reporter:Pucheng Pei, Minggao Ouyang, Qingchun Lu, Haiyan Huang, Xihao Li
International Journal of Hydrogen Energy 2004 Volume 29(Issue 10) pp:1001-1007
Publication Date(Web):August 2004
DOI:10.1016/j.ijhydene.2004.01.008
This paper is to present a test platform for automotive fuel cell systems and report some test results on this platform. The test platform was developed based on a test bed of internal combustion engine with a dynamometer, the dynamometer acted as both a load and a measurement instrument. A fuel cell engine, a DC/DC converter and an induction traction drive motor with a DC/AC inverter were integrated to a system and were tested in the platform. Test results of one fuel cell system showed that the efficiency was 41% (LHV) while of electrical power is produced in the engine; the cell current density was when of average cell voltage is obtained in the stacks; the maximum mechanical power of the fuel cell system was , and the best specific fuel consumption was . This test platform is feasible for evaluating all components of fuel cell systems, such as stacks, parasitic powers, engines, DC/DC converters and traction drive motors; and in this platform it is convenient to uncover problems of electromagnetism compatibility in the fuel cell systems before being mounted into vehicles.