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System Variants.

Single line measurement and differential measurement.

Single line measurement.

In the simplest case, a KRAL flowmeter can be installed before the mixing tank. It should be noted that KRAL fuel consumption measurement then only measures the refilling of the mixing tank. Fuel consumption is not measured and displayed in real time. However, over a longer measurement period, fuel consumption is very precisely correct. Where more than one engine is supplied with fuel from the mixing tank, fuel consumption measurement is no longer related to an engine. The total consumption of all engines together is measured.

The benefits of this type of installation are the low system price and easy operating conditions. The system is inexpensive because only one KRAL flowmeter and one BEM 300 are required. The operating conditions are less variable because the fuel pulses of the injection pumps have no effect on the feed line before the mixing tank. System measurement precision using one flowmeter is better than in the case of differential measurement.

Differential measurement.

With most engines, the return flow of the fuel ring line leads back into the tank. The additional quantity which is more then the fuel consumption depends on the circulation ratio. The circulation ratio determines the circulated quantity as a ratio to fuel consumption. If the engine is at full load, 3.5 will be a typical value, which means that 3.5 times as much fuel circulates as the engine consumes.

For precise measurement, one KRAL flowmeter must be installed in the supply line and one in the return line. For each engine, two KRAL flowmeters are required. The difference between the forward and return flow quantities indicates the consumption of fuel. The difference is calculated in the KRAL BEM 500 electronic units. Compensation for pressure pulses is controlled by KRAL pressure pulse compensation. KRAL temperature compensation takes account of the temperature difference between the forward and return flows. Very precise, variance-corrected measured values are thus ensured. The benefit of this type of installation is accurate, very fast consumption measurement. The measured value is immediately available in real time.

Multi-engine systems.

Ships, power plants and diesel locomotives often have multiple engines. To keep control of total fuel consumption, operators often demand fuel consumption measurement which can measure many engines. Displaying all consumption values measured on one display is often required. Fuel consumption measurement of an engine in a multi-engine system can be implemented as single line measurement or differential measurement. As an example, the illustration shows a system with 3 engines and 3 differential measurement systems.

The KRAL BEM 300, 500 and 700 electronic units each show the consumption values for one engine. The KRAL BEM 900 can display the consumption of up to 16 engines clearly on one display. KRAL electronic units support various bus systems. Even complex KRAL fuel consumption measurement can therefore be integrated into the electronic system installed on
board or in the control room.

 

KRAL AG | Bildgasse 40 | Industrie Nord | 6890 Lustenau | Österreich

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