Oil consumption measurements on combustion engines

Background

In modern engine development, the loss of engine oil represents a serious problem The downsizing of engines together with turbo charging and/or the reduction of piston ring thickness, in combination with increased cylinder pressure, leads to engine oil loss. Engine oil contains approximately 2000 - 3000 ppm of sulfur, which is oxidized during combustion, producing sulfur dioxide. This can lead to reduced catalyst activity.

In addition, other oil by-products such as phosphorus, compromise sensor properties, leading to faulty engine operation and catalytic converter function. To be able to minimize oil loss, it is necessary to know in which engine state it occurs. Gravimetric methods can provide information on static engine operating conditions, but for dynamic engine operation, real-time measurements are necessary to obtain time-resolved oil consumption profiles.

Solution

Sulfur dioxide measured in raw exhaust gas from internal combustion engines can be used as an indicator of oil consumption. With known fuel and lubricating oil sulfur concentrations, the oil consumption rate in g/h (grams per hour) can be calculated from the concentration of sulfur dioxide in the exhaust gas. The V&F GasOxidizer is used to convert all other possible sulfur components, including particulate-bound sulfur, into pure sulfur dioxide.

The highly sensitive V&F mass spectrometer can measure SO₂ concentrations up to 40 ppb with its IMR-MS technology. Typically, modern engines consume 2 to 3 grams of oil per hour, resulting in SO2 signals of 0.2 to 0.7 ppm SO₂ in raw exhaust when high sulfur (>5000 ppm S) oils are used.

Advantage

Using the SO₂ tracer method with our V&F mass spectrometers provides real-time data, allowing technicians to create the most accurate oil consumption profiles. In comparison, off-line methods such as gravimetry generally produce only two data points, before and after the test. They are also time-intensive and introduce significant sources of error.

In contrast to radioactive tracer methods, the setup and handling of our V&F analyzers is completely secure in terms of occupational safety. The V&F GasOxidizer facilitates the conversion of all the sulfur present in the exhaust gas stream both as a gas compound or as particles. Consequently, oil consumption measurement is possible on engines using different fuels such as gasoline, compressed natural gas, and diesel. The desired test cycles can be run immediately after the installation of the analyzer, without the need for access to the engine test bench.

Highlights

Real time oil consumption measurement
Time saving - Easy installation
For diesel, gasoline and natural gas engines

Reference clients (excerpt)

Suitable devices

V&F LubeSense

V&F GasOxidizer