scholarly journals ALTERNATIVE DESIGN AND ECONOMIC FEASIBILITY OF AN EXPERIMENTAL WHR FOR INTAKE AIR CONDITIONING OF A LARGE INTERNAL COMBUSTION ENGINE

2020 ◽  
Vol 19 (2) ◽  
pp. 31
Author(s):  
V. B. Paula ◽  
A. Chun ◽  
B. M. Miotto ◽  
C. C. M. Cunha ◽  
J. J. C. C. S. Santos

This work presents an alternative design for an experimental waste heat recovery thermal system to be coupled to a large turbocharged internal combustion engine for combustion air conditioning. The goal is to carry out a design of a new thermal system under restricted economic requirements for one of the generators set of Luiz Oscar Rodrigues de Melo Thermoelectric Power Plant. Thereby, a comparison with the original proposal from previous works is also developed in order to demonstrate the differences in terms of thermo-economic design parameters. The waste recovery thermal system produces sufficient chilled water through a single-effect absorption chiller, powered by hot water which is produced by recovering the exhaust gases residual heat to supply cooling applications on the combustion air. The results showed a significant reduction for the chiller capacity demand, from 550 to 185 RT, that would be enough to provide chilled water for 98.72% of the analyzed operation historical period. The economic feasibility indicators reveal the proposal for the alternative waste heat recovery system as the best financial option, presenting a lower investment cost (US$316,793.27 of savings) and a time for capital recovery of 2.14 years, 1.61 years shorter when compared with the initial WHR system.

Author(s):  
Manuel Jiménez-Arreola ◽  
Fabio Dal Magro ◽  
Alessandro Romagnoli ◽  
Meng Soon Chiong ◽  
Srithar Rajoo ◽  
...  

Waste heat recovery is seen as one of the key enablers in achieving powertrain of high efficiency. The exhaust waste heat from an internal combustion engine (ICE) is known to be nearly equivalent to its brake power. Any energy recovered from the waste heat, which otherwise would be discarded, may directly enhance the overall thermal efficiency of a powertrain. Rankine cycle (indirect-recovery method) has been a favorable mean of waste heat recovery due to its rather high power density yet imposing significantly lesser back pressure to the engine compared to a direct-recovery method. This paper presents the analytical investigation of a thermal-supercharged ICE compounded with Rankine cycle. This system removes the turbocharger turbine to further mitigate the exhaust back pressure to the engine, and the turbocharger compressor is powered by the waste heat recovered from the exhaust stream. Extra caution has been taken when exchanging the in/output parameters between the engine and Rankine cycle model to have a more realistic predictions. Such configuration improves the engine BSFC performance by 2.4–3.9%. Water, Benzene and R245fa are found to be equally good choice of working fluid for the Rankine cycle, and can further advance the BSFC performance by 4.0–4.8% despite running at minimum pressure setting. The off-design analyses suggested the operating pressure of Rankine cycle and its expander efficiency have the largest influence to the gross system performance.


Sign in / Sign up

Export Citation Format

Share Document