Page 32 - CARILEC CE Journal CEMAY2021

INTRODUCTION
The Wärtsilä 20V32LG engine is an internal Today, excluding marine applications, there are
compression ignition multi-fuel engine fired either approximately 807 Wärtsilä 32 engines operating
on liquid propane (pilot ignition source being diesel in 240 power plants producing 6,129 MW in 80
fuel) or diesel oil (LFO). This engine type is being countries. Similar statistics for the 32GD and 34
considered for the second phase of the WAPA DF engines are as follows: 32GD – 62 engines in
reciprocating engine power plant at the Randolph 12 plants producing 426 MW in 5 countries; 34DF -
Harley site in St. Thomas, USVI. Although basically 269 engines in 30 plants producing 2509 MW in 12
not a new engine, the 20V32LG engine has not been countries.
run commercially on liquid propane. However, The Wartsila 32/34 engine series is today available
its performance as shown in Table 2 below is in a multitude of configurations capable of operating
predictable on both propane and diesel oil and has on a wide variety of fuels ranging from LFO and HFO,
subsequently been confirmed n Wartsila’s test facility to associated gas, crude oil and liquid biofuels. The
in Vaasa, Finland. The emission numbers for the LG main engine types within the platform are:
engine shown in Table 1 below reflect the collective
experience of burning various liquid fuels in the
family of Wartsila 32 engines, namely the Wärtsilä
32 (HFO and LFO) and Wärtsilä 32GD (LFO and LPG)
engines. 32 (Diesel Cycle)
The 20V32LG engine is different from the spark traditional diesel, conventional or common rail
ignition units (designated 20V34-LPG) that are fuel injection system
installed in the first phase of the project and which
were previously reviewed by EPA and permitted by 32LG (Diesel Cycle)
the DPNR. The 20V34-LPG is an Otto cycle, lean burn liquid gas direct injection with diesel pilot fuel,
engine that operates on vaporized propane with the diesel fuel back-up mode
ignition source a high energy spark plug.
34DF (Otto Cycle)
This paper seeks to: pre-mixed gas injection with diesel pilot fuel,
(i) Explain the foundation and working principles diesel fuel back-up mode
of the Wärtsilä 32LG engine and the role that the
thermodynamic and stoichiometric characteristics 34SG (Otto Cycle)
play in the formation of certain pollutants as a result pre-mixed gas injection with spark-ignited gas
of the combustion process.
pre-chamber, natural gas

(ii) Provide assurances that Wärtsilä is providing its 34LPG (Otto Cycle)
best engineering estimate of the actual emissions pre-mixed gas injection with spark-ignited
that would be generated from this multi-fuel engine gas pre-chamber, LPG
– the Wärtsilä 32LG, based on the performance of the
32GD engine (Note: This paper was first prepared to Fuel injection pressures for the engine
give assurances to the EPA)
types above are as follows:
(iii) Present the emission abatement technologies 32 up to 1850 bar
that would be deployed in order to meet compliance 32LG up to 2,000 bar
levels for the various emissions.
34DF 4.5-6 bar for gas
34SG 4.5-6 bar
WARTSILA 32/34 ENGINE PLATFORM AND 34LPG 4.5 -6 bar
THE 32LG MULTI-FUEL ENGINE
The Wärtsilä 32LG (LG=Liquid Gas) is a diesel engine
that is a derivative of the ubiquitous Wartsila
32/34 engine series platform launched in 1996.

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