• Fuel Limiter (to ME)

6. Control and safety functionalities are separated on different hardware units

Some essential process information is monitored by having two sensors. One sensor is monitored by a control unit and the other sensor by a safety unit. Both sensors have to be operative to continue running on gas. If the sensor send to the safety unit is failing a gas shutdown is carried out and if the sensor send to the control unit fails a normal gas stop is carried out.

The gas injection is controlled from a control unit and the Window/Gas

Info no. Sub category Ident. no.

3092815 - 7

Title

Dual Fuel Operation Page no.

7 (28)

Date Des. Chk. Appd. A. C. Change/replacement C. no.

2011-03-16 JAB JAB ER Document transferred to template. 0

Shutdown valve is controlled from a safety unit (see ref.1)

7. Gas Shutdown & Window Valve with interlock to gas injection valves

In case of a leaking gas injection valve it is necessary to have a gas shutdown valve close to the gas injection valves in order to prevent a large gas leakage into the combustion chamber. This valve is also used as a window valve in order to avoid mistiming of the gas injection during gas running. The valve is in the following referred to as the window valve. The principle of the window valve and the hydraulic interlock is illustrated in annex 2.

The amount of gas between the window valve and the gas injection valves is limited, by mounting the gas block on the cylinder top cover, so that it will do no harm to the engine in case of a leaking gas injection valve.

The gas pressure in between the window valve and the gas injection valves are monitored in order to detect a leaking gas injection valve or a leaking window valve.

Gas Injection

The gas injection sequence is:

1. Window valve and gas injection valve are closed

Hydraulic control oil is supplied to the ELWI valve but not to the ELGI valve

2. Open window valve

The window valve is opened before gas is injected. The gas pressure in the gas accumulator propagate to the gas injection valve and hydraulic control oil propagate to the ELGI valve

3. Gas injection

The correct amount of gas is injected by timed opening and closing of the ELGI valve

4. Close Window valve

The sequence end by closing the window valve

Hydraulic safety precaution: control oil interlock

In the first step of the gas injection sequence there is no control oil supplied to the ELGI valve i.e. in case of a mistimed opening of the ELGI valve, the gas injection valve will not open.

Info no. Sub category Ident. no.

3092815 - 7

Title

Dual Fuel Operation Page no.

8 (28)

Date Des. Chk. Appd.