INSTALLATION (Cont.)

The unit consists of a V-12 four-stoke cycle Waukesha marine diesel engine directly coupled to a 300kW General Electric generator. The engine has a displacement of 1616 in³ and is rated at 525 hp at 1800 rpm. It is equipped with two turbochargers and burns No. 2 diesel fuel. The engine has attached fuel oil, lube oil, jacket water and raw water pumps. The raw water cools the jacket water and the jacket water cools the lubricating oil.

The engine is instrumented so that the mass flow rate of the fuel oil, intake air and raw water can be determined. The engine is also instrumented so that raw water temperature in and out of the jacket water cooler and the air intake and exhaust gas temperature can be determined. The flow rates and the temperatures are the basis of the heat balance. The generator can be connected to an electrical load bank so that load can be placed on the engine. The brake power output of the engine is determined by converting the kilowatt output to horsepower and dividing by the generator efficiency.

HEAT BALANCE

In a diesel engine, fuel is cornbusted inside the cylinder and the chemical energy of the fuel is released as thermal energy. The objective of the heat balance is to determine where the energy of the fuel is going. This gives a better understanding of the engine and is the basis for making improvements in engine efficiency.

Unfortunately, not all of the energy that is released in the combustion process can be utilized to push down on the piston and drive the load. Some of the energy is conducted through the walls of the cylinder and is picked up by the jacket water. Some of the energy leaves the engine in the exhaust gas. Some of the energy is lost overcoming friction in the engine and some is used to operate the intake and exhaust valves, fuel injectors, and engine driven pumps. The diesel engine heat balance allows for the determination of what percentage of the energy in the fuel is going to useful work and what percentages are lost to the cooling water, the exhaust gas and other losses.

EXPERIMENT

After agreeing to utilize the Waukesha diesel generator set as a test vehicle, the engine lubricating oil and filters were changed and the correct amount of Militec-1 was added to the oil. The engine was run on a number of occasions to allow the Militec-1 to bond to the surfaces of the engine.

The engine was then run on three different occasions with the power output set at 150kW and 250kW. The first two occasions were student laboratories and third occasion was a test run conducted by the author. The heat balance data was recorded at both loads on all three occasions creating six sets of performance data. The brake specific fuel consumption (bsfc), brake thermal efficiency, and heat balance were calculated for all six runs. These values were then compared to the data and calculated values from student laboratories prior to the addition of Militec-1. The pre-Militec data is presented in Enclosure (1) entitled Historical Laboratory Data. The post-Militec data is presented in Enclosure (2) entitled New Laboratory Data, Sept.'98 & March '99.

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