Wärtsilä Vasa is an engine series built by Finnish diesel engine manufacturer

Wärtsilä Wärtsilä Oyj Abp (), trading internationally as Wärtsilä Corporation, is a Finnish corporation, Finnish company which manufactures and services power sources and other equipment in the Marine propulsion, marine and energy markets. The core ...

. It was released in 1977 and remained in production until 2010. These medium speed diesels were produced in and named after Vasa, Finland. The lead designer of the first engine was Wilmer Wahlsted

The series comprises three models, the Vasa 22, 32, and 46, with the number denoting the Bore (engine), bore size of the engine. Wärtsilä discontinued production of the series in 2010 to focus on newer technology. The Vasa series acted as a precursor to the newer 32 D and E series which have a higher power output. Mistral-photo16

Models

* Vasa 14 * W16 * Wartsila Vasa 20 * Wärtsilä Vasa 22 * Vasa 24 * Wartsila Vasa 26 * Wärtsilä Vasa 32 * Wärtsilä Vasa 46

Technical data

The engines were designed for both shipboard and power plant applications. The engine could be ordered with a 220, 320, and 460 mm Bore (engine), bore in both V and inline configurations. The inline style was available with up to 9 cylinders and V could support up to 18. The VASA32LN engine was redesigned with a longer stroke to increase

horsepower Horsepower (hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. There are many different standards and types of horsepower. Two common definitions used today are t ...

. Vasa engines are turbocharged, non-reversible, and utilize a direct fuel injection system. They were designed to continuously run on

heavy fuel oil Heavy fuel oil (HFO) is a category of fuel oils of a tar-like consistency. Also known as bunker fuel, or residual fuel oil, HFO is the result or remnant from the distillation and cracking process of petroleum. For this reason, HFO contains seve ...

(HFO), provided that the fuel is pre-heated and at the correct viscosity at the time of injection. This is the power rating table generated for the Vasa 32LN engine. Engine power ratings are determined by how the engine is being used. The Vasa engines offer 375 kW/cyl and 410 kW/cyl. As the number of cylinders increase, the power increases. The size of the engine depends on the application it is being used for.Description of Engine, Technical Data. (2010). In Wärtsilä Engines: 32 product guide (2nd ed., Vol. 1, pp. 40 - 46). Vaasa: Wärtsilä.

Lubrication

Vasa engines utilize a circulating oil system for

lubrication Lubrication is the process or technique of using a lubricant to reduce friction and wear and tear in a contact between two surfaces. The study of lubrication is a discipline in the field of tribology. Lubrication mechanisms such as fluid-lubr ...

, complete with a main, pre-lubricating pump, and an oil cooler. Smaller Vasa engines use gear type pumps for lubrication where the larger engines use wheel type pumps.

Starting mechanism

Air is utilized to start the engines. Each cylinder head is equipped with a start air valve that delivers high-pressure air to the cylinder upon startup. This provides the engine the initial rotation force needed to achieve combustion.

Fresh water cooling

Treated fresh water is used for cooling of the cylinder, charge air,

turbocharger In an internal combustion engine, a turbocharger (also known as a turbo or a turbosupercharger) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake air, forcing more air into th ...

, and oil. Freshwater cooling is divided into two systems the HT (High Temperature) cooling the cylinders and turbocharger and the LT (Low Temperature) cooling the oil and charge air. The freshwater temperature is closely regulated with a thermostatic valve to achieve optimum efficiency. At low engine loads, the charge can be too cold, which can cause

incomplete combustion Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion ...

. To counteract this heat rejected to the lubrication oil can be used to heat the freshwater, which in turn heats the charge air enough to ensure complete combustion.

Control systems

Vasa engines can start remotely away from the engine or manually by manipulating the valves on the start air system. Upon startup engine speed is controlled by a

governor A governor is an politician, administrative leader and head of a polity or Region#Political regions, political region, in some cases, such as governor-general, governors-general, as the head of a state's official representative. Depending on the ...

, which mechanically adjusts fuel delivery to match the load demanded of the engine.Wärtsilä Vasa 32: Project guide for marine applications (2nd ed., Vol. 1997). (1989). Vaasa: . Diesel. Conditions are also in place to protect the engine. During operation, an engine will automatically cease injection if all preset conditions are not met.Kapulainen, M., Ronkainen, H., Hokkanen, A., Stuns, I., Varjus, S., Nyyssönen, S., . . . Halme, J. (2014). Fibre Optic Sensors for Long-Term Monitoring of Oil Film Pressure in Diesel Engine Main Bearing. Tribology Letters, 56(1), 47-54.

Applications

These engines are primarily used for

power generation Electricity generation is the process of generating electric power from sources of primary energy. For utilities in the electric power industry, it is the stage prior to its delivery ( transmission, distribution, etc.) to end users or its stora ...

and diesel-electric propulsion plants. Since they are non-reversible, they are not widely used as propulsion engines. The engines were used to provide electrical power for both propulsion and auxiliary services. Due to their ability to run on heavy fuel oil (HFO) or MDO (

Marine Diesel Oil Marine diesel oil (MDO) is a type of distillate diesel oil. Marine diesel oil is also called ''distillate marine diesel''. MDO is widely used by medium speed and medium/high speed marine diesel engines. It is also used in the larger low speed and m ...

), many ships were equipped with the Vasa series engines. In the power generation industry, these engines are used as auxiliary generators or as backup power generators.McNeely, M. (2003). Reliable Island Power from Wärtsilä. Diesel and Gas Turbine Worldwide, 35(8), 10-12.

References

Vasa Science and technology in Finland {{Finland-stub fi:Wärtsilä#Dieselmoottorit