Bài soạn Trang tri he dong luc tau thuy 1

 Kinds of following main engine can be used: Steam engine, steam turbine, gas turbine, diesel engine, and “generator - motor”  Diesel engine is mostly used nowadays..  In the marine p

Faculty of Marine Engineering

Viet Nam Maritime University

6 years of teaching and working on board the foreign and Viet Nam Ship.

Purpose of the Subject

 Introduce main requirements of

propulsion ‘s designing follow

 Total: 75 periods,

◦ 45 periods for theory

◦ 30 periods for practical and simulation

 General contents

◦ Chapter 1: Notions of Marine propulsion plant

◦ Chapter 2: Shafting and it’s components

◦ Chapter 3: Mode of driving and driving

mechanisms

◦ Chapter 4: Vibration

◦ Chapter 5: Systems of Marine propulsion

plant

Chapter 1

Notions and classification

of Marine Propulsion Plant

Total: 6 periods

Lesson 1: Notions of MPP

 What is MPP?

 MPP consists of:

◦ Main propulsion equipment

◦ Auxiliary propulsion equipments

◦ Safety equipment

◦ Equipment of serving domestic

requirement

◦ Deck ‘s equipment

 Kinds of following main engine can be used:

Steam engine, steam turbine, gas turbine, diesel engine, and “generator - motor”

 Diesel engine is mostly used nowadays Besides

this, on modern ships newly manufactured with large power, the steam turbine propulsion plants are being developed

 In the marine propulsion plant, one or more

main engine can be used.

 Non controllable - pitch propeller

 Controllable - pitch propeller

◦ Main boiler is used only on steam ship.

e. Conveyance equipment

◦ They are used to convey working substance to a main engine They consist of steam tube, gas tube

b Compressed air system

◦ Generates and stores compressed air with high pressure for starting and reversing the main engines, starting generator engines, cleaning parts of the engine

◦ Compressed air is also used in remote control and automatic control systems Compressed air system consists of compressors, reservoirs (air tank), non-reversible valves, relief valves, and compressed air pipes

c Auxiliary boiler

◦ Supplyes steam to heat fuel, water, diesel engine (before starting) and cabins In addition, it also serves steam machineries and equipment (such as cargo pumps on tanker ships).

Lesson 1: Notions of MPP

3 Safety equipment of MPP.

To undertake the safe operations of the ship in every condition to limit damages due to trouble Safety equipment consists of:

a Bilge system

b Ballast system

c Fire protection system

d Repairing equipment, store and spare

parts for replacing.

5. Deck's equipment

◦ They consist of steering gear, mooring

winches, cargo winches, life equipment (life boats, life rafts an so on ).

Lesson 2: Classification of MPP

1. Steam propulsion plant

◦ Steam engine

◦ Steam turbine

2. Diesel engine propulsion plant

◦ Apply almost on the ship nowadays

◦ Many type of diesel engine, such as:

 Low speed marine diesel engine

 Medium speed marine diesel engine

 High speed marine diesel engine…

3. Other

◦ Gas turbine propulsion plant

◦ Nuclear propulsion plant

(Student read more this problem in text book)

Lesson 3: Technical

characteristic of MPP

1 Technical characteristics of

diesel engine propulsion plant.

◦ Working substance is combustion of air - fuel

◦ Thermal efficiency is high, SFC is low

◦ Output is not continuously generated

◦ Generate reciprocating forces and inertia moments when working

◦ Engine parts withstand forces vary cyclically.

◦ Immediate pressures and tempretures in the engine combustion chamber are very high

1 Technical characteristics of

diesel engine propulsion plant.

◦ Diesel engines can be easily reversed by change work order of starting mechanism

◦ In light load conditions, diesel engines are not working economically and stably

◦ It is flexible because of short time for starting

◦ Heat energy, which goes out of engine with gas is high; so that we can re-use

◦ Efficiency of Diesel engine MPP about 35 – 55%

2 Technical characteristics of steam

turbine propulsion plant.

generated in main boiler

◦ Output is continuous

◦ Working substance flows continuously through the

turbine so rotating moment, heat and mechanical load in the parts of engine are stable Therefore, turbine has a high longevity

◦ All moving parts of turbine are installed on a rotor,

rotated with the same certain direction and speed

It permits to reduce mechanical losses, raise efficiency of turbine When working, turbine doesn't generate inertia forces

◦ Output of turbine depends on only parameters and

amount of steam that flow through turbine So turbine can generate a large power

2 Technical characteristics of steam

turbine propulsion plant.

◦ Turbine direction is determined by direction of steam, which acts on blades wheel of turbine With a certain blade wheel, turbine cannot reverse its self.

◦ Turbine's revolution is much higher than optimum range of propeller's revolution, so turbine cannot directly drive propeller

◦ Gas temperature in boiler combustion chamber is limited by heat durability of material Cycle temperature is low; boiler and transmission pipes have heat losses so efficiency of propulsion plant is low

◦ Efficiency of the steam turbine propulsion plant is about 22  26%

◦ High pressure and temperature steam flows continuously inside transmission pipes It may cause danger to operators when emergency happens.

◦ It requires having a high quality of water in the system.

◦ It takes a long time to prepare for starting the system, so it is not flexible.

Lesson 4: Interaction between

Hull and Propeller.

 Student prepare and answer the following questions:

1 How many type of resistance act to

the ship? And calculate them?

2 How to calculate ME power from

the resistance?

3 Why actual ME ‘s power always

higher than that from calculate?

Lesson 5: Requirements of Marine Propulsion Plant

To operate the ship safely and economically,

a marine propulsion plant has to satisfy the general requirements as follow:

◦ The transformation of energy is optimum

◦ Equipment are simple

◦ It is safe and trustful

◦ Dimension and weight are small

◦ Longevity is high

◦ Cost must be low

In fact, to meet all these requirements

together is very difficult To simplify it, we

study the following requirements;

Lesson 5: Requirements of

Marine Propulsion Plant

1. Requirement about the power of marine

propulsion plant according to propeller and hull characteristics

2. Requirement about economical norm of marine propulsion plant

3. Requirements of propulsion plant for

independent working ability of the ship

a Requirement about the weight of propulsion plant.

b Requirement about dimension of the engine room.

c Requirement about the needs of the propulsion

Finished chapter 1