7 семестр (Бормотов А) / 1man_bw_l23_30_chn_23_30_instruktsiya_po_ekspluatatsii / MAN-BW L23-30 (ЧН 225_300)+ / MAN-BW L23-30h project-guide

Description

The fuel changing system consist for GenSet of two three-way valves (V1 and V2) with a electric/ pneumatically operated actuator of the simplex type with spring return and a common valve control box for the total GenSet plant.

The system facilitates a flexible selection of MDO and HFO-operating at any load condition. This system gives the advantage of individually choosing MDO or HFO mode of operation of the GenSets.

To maintain recirculation in the HFO flow line when the GenSet is operated on MDO a by-pass valve must be installed between the inlet changing valve (V1) and the outlet valve (V2) at each GenSet as shown in fig. 1.

Valve Control Box

Electrical power supply to the valve control box is 380 Volt - 50 Hz, or 440 Volt - 60 Hz, depending on the plant specification, and is established in form of a single cable connection from the switchboard.

Pipe description

Flange connections are as standard according to DIN 2501

General

As standard the lubricating oil system is based on wet sump lubrication.

All moving parts of the engine are lubricated with oil circulating under pressure in a closed built-on system.

The lubricating oil is furthermore used for the purpose of cooling the pistons.

The standard engine is equipped with built-on:

–Engine driven lubricating oil pump

–Lubricating oil cooler

–Lubricating oil thermostatic valve

–Full-flow depth filter

–Prelubricating oil pump

Oil Quantities

The approximate quantities of oil necessary for a new engine, before starting up are given in the table on the next page.

If there are connected external, full-flow filters etc., the quantity of oil in the external piping must also be taken into account.

Table 1 Quantities for starting-up the engine incl. cooler, filters and pipes on engine.

Max. velocity recommendations for external lubricating oil pipes:

Lubricating Oil Consumption

The lubricating oil consumption of MCR is:

Table 2 Lubricating oil consumption, tolerance ±25%

It should, however, be observed that during the running in period the lubricating oil consumption may exceed the values stated.

Quality of Oil

Only HD lubricating oil (Delegent Lubricating Oil) should be used, characteristic stated in "Lub. oil spec. B 12 15 0".

System Flow

The lubricating oil pump draws oil from the oil sump and presses the oil through the cooler and filter to the main lubricating oil pipe, from where the oil is distributed to the individual lubricating points. From the lubricating points the oil returns by gravity to the oil sump.

The main groups of components to be lubricated are:

1 – Turbocharger

2– Main bearings, big-end bearing etc.

3– Camshaft drive

4– Governor drive

5– Rocker arms

6 – Camshaft

1)For priming and during operation, the turbocharger is connected to the lub. oil circuit of the engine, the oil serves for bearing lubrication and also for dissipation of heat.

The inlet line to the turbocharger is equipped with a fixed throttle in order to adjust the oil flow and a non-return valve to prevent draining during stand-still.

The non-return valve has back-pressure function requiring a pressure slightly above the priming pressure to open in normal flow direction. In this way overflooding of the turbocharger is prevented during stand-still periods, where the prelubricating pump is running.

2)Lubricating oil for the main bearings is supplied through holes drilled in the engine frame. From the main bearings it passes through bores in the crankshaft to the connecting rod big-end bearings.

The connecting rods have bored channels for supply of oil from the big-end bearings to the small-end bearings, which has an inner circumferential groove, and a pocket for distribution of oil in the bush itself and for supply of oil to the pin bosses and the piston cooling through holes and channels in the piston pin.