TPS - HIGH EFFICIENCY, HEAVY DUTY TURBOCHARGER FOR MEDIUM SIZE ENGINES
Hansruedi Born*, Takashi Akita**
Within the past few years the development of small medium-speed diesel engines has been rapid and intense. In order to fulfill the current as well as future requirements of these market segments, ABB Turbo Systems Ltd. introduced a new turbocharger series, the TPS..D/E. This series of four different turbocharger sizes offers a high efficiency level combined with a high pressure ratio capability. These are prerequisites for the development of diesel engines toward higher specific power, but can also be used in connection with the Miller process to reduce the emission level of existing engines in order to comply with future emission regulations. This paper describes the major customer benefits and the main features of this new turbocharger series. Some specific results of the turbocharger's comprehensive mechanical testing program are presented as well as field test experience with regard to thermodynamics & mechanical behaviour under heavy fuel conditions.
Key Words: Turbocharger
Modem small medium-speed diesel engines, large high-speed diesel engines and gas engines in the power range between 500 kW and 3200 kW require a turbocharger that fulfills the following criteria:
・a high potential in pressure ratio (up to 4.7) to increase power output
・a high efficiency to reduce fuel consumption and exhaust temperatures
・a compact design which results in small overall dimension, low turbocharger weight and, therefore, acceptable performance cost
・a high quality standard, a proven reliability and endurance to reach appropriate TBO even under adverse conditions such as operation with heavy fuels (small medium-speed engines)
In response to these market requirements, ABB Turbo Systems Ltd. developed the TPS..D/E turbocharger family. The design of the TPS..D/E is completely new and based on experiences made with the RR.. 1 turbocharger series , of which there are approximately 26000 units currently in service.
A detailed market analysis of the three aforementioned engine types led to the conclusion that four turbocharger sizes and two compressor stages with different pressure ratios and volume flow rates are needed to match the current and future requirements for the considered engines and their specifications such as mean effective pressure, speed, number of cylinders and operating lines. In Fig.1 these four turbocharger sizes with their corresponding volume flow rates and full load pressure ratios are compared with recognized ABB turbochargers which are still used in the Japanese market. "Line 1" in Fig.1 shows the effect of an increase in mean effective pressure on the turbocharger operating point.
Fig.1: Volume flow rate of the TPS..D/E turbocharger series compared with the VTR.. 1 series