3.6 Turbocharger - Exhaust Gas System
Generally, high output and high-speed engine needs the turbocharger, which has high-pressure ratio capability, overall efficiency and a compact design. V20FX used TPS series turbocharger manufactured by ABB Turbo Systems Ltd. Using the TPS series turbocharger, we achieved such a high output only two turbochargers.
And, in order to reduce the exhaust gas temperature, we adopted one line exhaust manifold system on each half a bank. This system has already adopted Niigata FX series.
Therefore, V20FX achieved such a high performance by a simple structure compared with the other engine, which has similar output.
4. PERFORMANCE
We conducted various detailed analyses on principal components and carries out individual element tests. After that, we manufactured some engines and conducted performance tests.
Especially from combustion characteristic measurement, short period combustion can be seen. Furthermore, thanks to the lower Pmax/Pcomp combustion while keeping good performance, NOx emission is very low. The NOx level of V20FX and V16FX is 8.95 and 8.68 g/kWh in the IS08178 E3 mode. They went significantly below the draft of IMO regulation as shown in Fig.7.
Fig 8 shows the performance of V20FX. The specific fuel consumption of V20FX is 211 g/kWh at maximum continuous output.
We also performed cycle load operations that imposed serve thermal stress to endurance test when the engine is operated for an extended period at a constant load. We confirmed that there were no defects after the endurance test by disassemble the components.
5. CONCLUSIONS
To realize high power density engines, structural analyses, heat transfer analyses, thermal stress analyses and component tests have been conducted. From the results, significantly light and high output engine has been developed and demonstrated the functions of the new engines through durability tests that included cyclic load.
6. ACKNOWLEDGMENT
The authors acknowledge the permission of the Directors of Niigata Engineering Co., Lid. to publish this paper. They also acknowledge the contributions of numerous colleagues to these developments.
7. REFERENCES
[1] Yaguchi K, Nakanishi T, Koishi D and Akiyama M. "Development of V16FX and V26FX High-speed Diesel Engine for Fast Commercial Vessel", 21th CIMAC, 1995, D21
[2] Snkoh S. "Investigation on Safety Factor of Main Parts of Diesel Engine in Design Work", 20th CIMAC, 1993, D43
[3] Iwasawa K, Matsuda S. Mizuno Y and Mochizuki M. "Evaluation of Wear between Journal Shaft and Bearing Materials in Diesel Engines" 51st Preprint of M.E.S.J. (in Japanese), 1993, No.211
