“AHX-DF” that meets IMO Tier III NOx Regulations
NIIGATA Power Systems Co., Ltd., (Niigata) has developed and started
sales of the 2,000 kW class medium-speed dual fuel marine engine
“AHX-DF” that meets International Maritime Organization (IMO) Tier III
NOx regulations start applying from 2016. AHX-DF is a dual fuel engine
that runs either on diesel fuel or natural gas, and NOx emissions are
reduced by 75% from the current IMO Tier II compliant engines of
Niigata. This leads to substantial reduction of environmental load
complying with IMO Tier III NOx regulations.
Advantages of AHX-DF engine are as follows.
(1) Excellent acceleration response in gas
operation mode
Speedy acceleration from startup to 100% load operation is a critical
factor for the marine engine. It was understood that the gas engine is
not as good as the diesel engine for load increase rate. The load
increase rate of the AHX-DF in gas operation is substantially improved
and comparable with the diesel engine.
(2) Switching between gas operation and diesel
operation possible at any time from startup to 100% load operation
Conventional dual fuel engines switching between gas operation and
diesel operation was only possible when the engine ran below 80% load.
In the case of the AHX-DF, switching of operation mode is possible at
even if 100% load, which allows continued safe ship operation by
switching the operation mode in an emergency.
(3) Stable operation during rapid load
increase in gas operation
It was understood that stable ship operation was difficult with a gas
engine due to possible abnormal combustion during rapid load increases.
Niigata applied the superior gas combustion technologies acquired
through the development of gas engines for stationary power plants to
the AHX-DF and successfully reduced abnormal combustion during rapid
load increases.
(4) Allows selection of suitable operation
mode depending on the sea area
The dual fuel feature of the AHX-DF allows flexible selection of
operation mode: gas operation in IMO NOx emission control areas and
diesel operation in other sea areas. This makes compliance with IMO Tier
III NOx regulations without after-treatment devices.
Niigata continues the development of marine engines that will reduce
the impact on the environment and provides engines for safe and
environmentally friendly ship operations.
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