0
Research Papers: Fuel Combustion

# Numerical Study on Fuel Preheating at Cold Start Phase in an Ethanol Flex Fuel Engine

[+] Author and Article Information
Ying Wang

School of Energy and Power Engineering,
Xi'an Jiaotong University,
Xi'an 710049, China
e-mail: yingw@xjtu.edu.cn

Zhensheng Liu

School of Energy and Power Engineering,
Xi'an Jiaotong University,
Xi'an 710049, China
e-mail: 1293207078@qq.com

1Corresponding author.

Contributed by the Internal Combustion Engine Division of ASME for publication in the JOURNAL OF ENERGY RESOURCES TECHNOLOGY. Manuscript received August 2, 2017; final manuscript received March 11, 2018; published online April 16, 2018. Assoc. Editor: Avinash Kumar Agarwal.

J. Energy Resour. Technol 140(8), 082207 (Apr 16, 2018) (8 pages) Paper No: JERT-17-1400; doi: 10.1115/1.4039740 History: Received August 02, 2017; Revised March 11, 2018

## Abstract

The low vapor pressure of ethanol and the high latent heat of vaporization at low temperatures cause the difficulties of cold start in a flex fuel vehicle when it is fueled with pure ethanol. Preheating fuel is one of the effective methods to solve the above cold start problem. Thus, it is crucial to obtain the fuel temperature distribution in the heating system for fuel preheating process. For this purpose, the numerical analysis is adopted here to simulate the fuel preheating process at a cold start phase and explore the change of the fuel temperature field under different influence factors. The results indicate that the starting temperature has obvious impact on the temperature field distribution in the heating chamber and preheating time but has little effect on the volume of cold fuel in the connecting line at the end of heating. When the starting temperature is −5 °C, the preheating time is 8.3 s. When the starting temperature increases up to 15 °C, the preheating time will decrease as 4.9 s. Furthermore, the lower the starting temperature is, the higher the overall temperature of the heating chamber is. The installing angle of injectors has some influence on the temperature field distribution, and the cold fuel ratio reduces slightly when the angle increases from 30 deg to 60 deg. The calculation results indicate that the temperature of fuel at the injector inlet is above 20 °C, and the fuel injected during the first three cycles of the engine operation is hot fuel.

<>

## References

Roberts, A. , Brooks, R. , and Shipway, P. , 2014, “ Internal Combustion Engine Cold-Start Efficiency: A Review of the Problem, Causes and Potential Solutions,” Energy Convers. Manage., 82, pp. 327–350.
Yanowitz, J. , Knoll, K. , Kemper, J. , Luecke, J. , and McCormick, R. L. , 2013, “ Impact of Adaptation on Flex-Fuel Vehicle Emissions When Fueled With E40,” Environ. Sci. Technol, 47(6), pp. 2990−2997. [PubMed]
Nicolas, G. , and Metghalchi, H. , 2016, “ Development of the Rate-Controlled Constrained-Equilibrium Method for Modeling of Ethanol Combustion,” ASME J. Energy Resour. Technol., 138(2), p. 022205.
Wei, Y.,J. , Wang, K. , Wang, W. R. , Liu, S. H. , and Yang, Y. J. , 2013, “ Contribution Ratio Study of Fuel Alcohol and Gasoline on the Alcohol and Hydrocarbon Emissions of a Gasohol Engine,” ASME J. Energy Resour. Technol., 136(2), p. 022201.
Dardiotis, C. , Fontaras, G. , Marotta, A. , Martini, G. , and Manfredi, U. , 2015, “ Emissions of Modern Light Duty Ethanol Flex-Fuel Vehicles Over Different Operating and Environmental Conditions,” Fuel, 140, pp. 531–540.
Fernando de, O. J. , Fernando, L. , Franco da Silva, L. L. , Luiz Fernando de, B. O. , and Tulio, I. M. C. , 2015, “ Warm Start Robustness Improvement Using the Heated Cold Start System in Flex Fuel Engines,” SAE Paper No. 2015-36-0202.
Krenus, R. , Passos, M. R. V. , Ortega, T. , Mowery, K. , Kim, Y. J. , Lucille, G. L. , Lee, K. , Park, C. J. , and Han, K. , 2014, “ Ethanol Flex Fuel System With Delphi Heated Injector Application,” SAE Paper No. 2014-01-1369.
Cordeiro de Melo, T. C. , Machado, G. B. , Belchior Carlos, R. P. , Cola, M. J. , Barros, J. E. M. , Oliveira, E. J. , and Oliveira, D. G. D. , 2012, “ Hydrous Ethanol–Gasoline Blends—Combustion and Emission Investigations on a Flex-Fuel Engine,” Fuel, 97, pp. 796–804.
Monteiro, S. L. C. , Barbosa, R. F. , Oliveira, F. M. V. , Leal, W. F. , and Valdivino da Silva, Z. , 2010, “ Heating System for Ethanol and Intake Air—Numerical Model and Experimental Validation at Cold Start in a Flex Fuel Vehicle With Emissions Analysis,” SAE Paper No. 2010-36-0412.
Charoenphonphanich, C. , Imerb, W. , Karin, P. , Chollacoop, N. , and Hanamura, K. , 2011, “ Low Temperature Starting Techniques for Ethanol Engine Without Secondary Fuel Tank,” SAE Paper No. 2011-32-0552.
Malagó Amaral, T. M. , Moreira, F. , Yoshino, F. J. , Cavalhieri, H. M. , Diniz da Cruz, R. J. S. , and Schadler, W. , 2014, “ Self-Controlled Electronic Cold Start System for Flexible Fuel Vehicles,” SAE Paper No. 2014-36-0208.
Monteiro Sales, L. C. , and Sodré, K. R. , 2012, “ Cold Start Emissions of an Ethanol-Fuelled Engine With Heated Intake Air and Fuel,” Fuel, 95, pp. 122–125.
Monteiro Sales, L. C. , and Sodré, K. R. , 2012, “ Cold Start Characteristics of an Ethanol-Fuelled Engine With Heated Intake Air and Fuel,” Appl. Therm. Eng., 40, pp. 198–201.
Iodice, P. , Senatore, A. , Langella, G. , and Amoresano, A. , 2016, “ Effect of Ethanol–Gasoline Blends on CO and HC Emissions in Last Generation SI Engines Within the Cold-Start Transient: An Experimental Investigation,” Appl. Energy, 179, pp. 182–190.

## Figures

Fig. 1

Schematic view of cold start system based on heated fuel rail

Fig. 2

The simplified actual model: (a) model overall structure and (b) model internal structure

Fig. 3

The schematic diagram of installation direction of fuel injector and heating chamber

Fig. 4

PTC characteristic curve of temperature versus power

Fig. 5

Sketch map of model calibration experiment

Fig. 6

Comparison of simulated temperature values and experimental temperature values at the monitoring point

Fig. 7

The location of monitoring points

Fig. 8

Temperature variation curve of monitoring points with a different number of grids

Fig. 9

The temperature field distribution of the heating chamber at heating period: (a) section 1 and (b) section 2

Fig. 10

The spatial distribution of fuel temperature in the heating chamber

Fig. 11

The fuel temperature distribution at the end of heating under various starting temperatures: (a) T = −5 °C, (b) T = 0 °C, (c) T = 5 °C, and (d) T = 15 °C

Fig. 12

The fuel volume ratio at the end of heating under various starting temperatures

Fig. 13

The cold fuel volume ratio in the connecting line at the end of the heating under various starting temperatures

Fig. 14

Comparison of fuel temperature profiles under various angles: (a) slide 1 and (b) slide 2

Fig. 15

Comparison of volume fraction of fuel in heating chamber under various angles

Fig. 16

Comparison of cold oil ratio in the connecting lines under various angles

Fig. 17

The temperature profile at different times with the injection: (a) t = 9 s, (b) t = 9.05 s, (c) t = 9.2 s, (d) t = 9.4 s, (e) t = 9.6 s, and (f) t = 9.8 s

Fig. 18

The average fuel temperature at the injector inlet after fuel preheating

## Errata

Some tools below are only available to our subscribers or users with an online account.

### Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related Proceedings Articles
Related eBook Content
Topic Collections