HEAT EXCHANGER BY SMOOTH TUBE FOR RECOVERING, UTILIZING THE EXHAUST GAS ENERGY OF SMALL DIESEL ENGINE AIMING AT HEATING PURE VEGETABLE OIL

Author(s): 

Thi Minh Hao Dong and Van Huong Dong*

Affiliation(s): 

Ho Chi Minh University of Transport, Ho Chi Minh city, Vietnam

*Corresponding Author E-mail: huong_dv@ut.edu.vn

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Diesel engines with high combustion temperature and pressure are considered as the energy source more efficient than another thermal equipment or engines. The exhaust gas energy of small diesel engines has almost not been studied to recover aiming at improving the total thermal efficiency. Besides, mineral fuel using for diesel engines is being depleting. The combination between utilizing the exhaust gas energy of small diesel engine to heat up bio-oils, and using heated bio-oils as the alternative fuel will not only satisfy the ever-increasing energy demands of the human, save energy, reduce the environmental pollution and the dependence on fossil fuel, but also contribute the efficient energy use. The paper presents the calculation, design, and fabrication results of a bio-oil heating system for a diesel engine D243 by direct utilizing exhaust gas energy and using heated bio-oil as fuel in that diesel engines. This system is installed in experimental diesel engine to determine the exhaust gas temperature and check the working features of engine at 10%, 25%, 50%, 75%, 100% of engine load, and 1500 rpm, 2000 rpm of engine speed. Besides, the resistance in the exhaust pipe is calculated and shown the results of 191 Pa at 75% of load and 468 Pa at 100% of load in comparison with 1472 Pa of requirement, and the simulation of intake and outtake exhaust gas temperature from heat exchanger by ANSYS FLUENT is carried out to compare to experiment results. The paper results show that, after installing the heat exchanger in the engine exhaust pipe for heating bio-oils and using heated bio-oils as fuel, the technical indicators of experimental engine are guaranteed, the difference between simulation and experimental results is not significant, the average of utilized exhaust gas energy is about 52%.