Thermodynamic and feasibility analysis of using diesel generator exhaust gases for ship main engine preheating at port periods


ÇOLAK K., ÖLMEZ H.

APPLIED THERMAL ENGINEERING, vol.235, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 235
  • Publication Date: 2023
  • Doi Number: 10.1016/j.applthermaleng.2023.121429
  • Journal Name: APPLIED THERMAL ENGINEERING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, PASCAL, Aerospace Database, Business Source Elite, Business Source Premier, Communication Abstracts, Compendex, INSPEC, Metadex, DIALNET, Civil Engineering Abstracts
  • Keywords: Diesel generator, Fuel saving, Heat exchanger, Marine diesel engine preheating, Performance criteria, Waste heat recovery
  • Karadeniz Technical University Affiliated: Yes

Abstract

In this study, the feasibility and potential impact on fuel consumption of the proposed preheating system driven by diesel generator exhaust gas instead of steam to satisfy main engine pre-heating demands especially under port operation conditions have been analyzed according to the 1st and 2nd laws of thermodynamics. The proposed novel term named performance criteria (PC) and exergy efficiency (& epsilon;) values of the main engine preheating and cooling water systems of the Ro-Ro ship selected for the case study under the existing voyage and port operating conditions have been determined by written Matlab-2021a codes merging CoolProp-6.4.2 database with Python. It was determined that even at the lowest operating load of the diesel generator (25%), the exhaust heat energy would be sufficient to preheat the main engine with also reducing the fuel consumption. As a result, during the 12-hour port period, 22% of the boiler fuel consumption and 8% of the ship's fuel consumption can be saved. Accordingly, if a shipping company uses Mine Gas Oil as fuel, it will be able to achieve fuel savings of approximately US$ 32.000 on annual basis. Considering the fuel saving values, it has been determined that 1.016 tons of CO2 emissions for per port operation and 106 tons of annual CO2 emissions can be reduced. It was determined that, the PC and & sigma; values of the system decrease as the ambient temperature increases. In this context, there is a 7% decrease in the PC and a 5% decrease in the & sigma; for existing system and 8% decrease in the PC and a 2.5% decrease in the & sigma; for proposed system. It was also determined that the proposed new system is both physically and economically feasible and that the investment cost, which was determined to be in the range of US$ 30.000-US$ 35.000, can pay for itself after 1 year.