Thermodynamics Lab Report Complete PDF

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Thermodynamics Lab Report Complete BASIC PARTS OF AN IC ENGINE...

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University of engineering & technology, Peshawar

Name: Reg. No. Semester: Department: Section/C.No. Course:

LABORATORY REPORT - II INTRODUCTION TO BASIC PARTS OF AN IC ENGINE

Objective: The main objective of this laboratory is to get familiar with an Internal Combustion (IC) Engine, its components, working and functions of its various components.

Abstract: Introduction The aim of this report is to introduce the various components of an IC Engine found in the Thermodynamics Laboratory. The study was made in the Department of Mechanical Engineering of the University of Engineering and Technology Peshawar in which thirty-one students participated. The report introduces different components of an IC Engine along with an elaborate description of their function and purpose.

Key Words IC Engine, Cylinder, Piston, Crankshaft, Mechanical Energy

General Safety in the Lab: In a recent research article published in the iRED (Institute of Research for Engineers and Doctors) it was clearly stated that of all the labs to be performed during Bachelor of Engineering in the field of Mechanical Engineering, the Thermodynamics laboratory presents the most potential hazard conditions. There are fuel vapours, hot surfaces, high temperatures, and rotating machinery. It is essential that the lab procedures be followed explicitly. The following considerations must be acted upon: 1. All students/visitors must obey instructions of lecturer/ technician or other staff member regarding safety. Not allowed to refuse according to the law. 2. When siren sounds or instructed by safety officer, leave building immediately through nearest exit. 3. Avoid internal combustion engine lab if fire alarm sounds. 4. No unauthorized persons may enter a lab or workshop

5. Report all safety risks to the technician/lecturer/ chairperson. For Example, unsafe/faulty electrical wiring or cables, compressed air pipes/hoses, etc. 6. Report all incidents in which a person is injured immediately to the technician/lecturer/chairperson. 7. Safety shoes (hard toe) compulsory when moving heavy objects. 8. No loose clothes or long hair near moving machines. 9. Make sure your know where the nearest fire extinguisher or hose is before you start working in the lab. 10. No smoking allowed anywhere in the building, or within 20 m of an entrance. 11. When working in a lab where vapors or gasses can accumulate, you must personally ensure that the area is well ventilated. 12. Fuels, paints and other flammable substances, substances that give off vapours, chemicals, acids, etc must be stored in the correct way and the correct store room. 13. If taking new medication, do not operate machinery until you know how it effect you. 14. If you are sleep deprived, do not operate machinery.

What is an Engine?

Definition The combination of different machine components that arrange in such a manner that it converts heat energy into Mechanical Energy is known as an Engine. Thus we can say that an engine is basically a machine that converts Power into motion, for example the Power obtained from burning fuel results in the locomotion/movement of an automobile.

Types of Engines In general, there are many types of engines such as Combustion Engines, Electrical Engines or motors and Molecular or Natural Engines which uses chemical energy inside organisms or systems to define a state. Here in the Thermodynamics laboratory we study two Particular types of a Combustion Engine. (See Figure 1 and Table 1)

Combustion Engine

Internal Combustion (IC) Engine

External Combustion (EC) Engine

Figure 1 Types of Combustion Engines

Type of Combustion Engine

Function/Purpose

1. Internal Combustion Engine

In this type of engine, the process of combustion takes place internally.  Generally, an IC Engine is defined as an engine which generates motive power by the burning of petrol, oil, or other fuel with air inside the engine, the hot gases produced being used to drive a piston or do other work as they expand.  For Example: Automobile  In this type of Engine, the process of combustion takes place externally.  Generally, an EC Engine is defined as a heat engine where a working fluid, contained internally, is heated by combustion in an external source, through the engine wall or a heat exchanger. The fluid then, by expanding and acting on the mechanism of the engine, produces motion and usable work. The fluid is then cooled, compressed and reused (closed cycle), or (less commonly) dumped, and cool fluid pulled in (open cycle air engine).  For Example: Steam Engine

2. External Combustion Engine



Table 1 Functions of an IC & EC Engine

Figure 2 Schematic Model of an IC Engine

Components of an IC Engine: The following major components of an IC Engine and their functions are elaborated:

1. Cylinder Block:   

Foundation of an Engine, All other parts are assembled in it, It is mostly made up of Aluminium alloy or an iron alloy.

2. Cylinder Head:  

Basically it covers cylinder block, Literally it is the end cover of a cylinder in an internalcombustion engine, against which the piston compresses the cylinder's contents.

Figure 3 Cylinder Block and Cylinder Head

3. Cylinder:    

Burning of Fuel occurs inside cylinder, Piston also lies here and moves up and down, Basically it is a cylindrical shape vessel fitted in cylindrical block, A cylinder is the central working part of a reciprocating engine or pump, the space in which a piston travels. Multiple cylinders are commonly arranged side by side in a bank, or engine block, which is typically cast from aluminum or cast iron before receiving precision machine work. Cylinders may be-sleeved (lined with a harder metal) or sleeveless (with a wearresistant coating such as Nikasil). A sleeveless engine may also be referred to as a "patentbore engine".

Figure 4 Cylinder in Phase I of an IC Engine

4. Piston:    

It is a moving component of an IC Engine, It compresses air-fuel mixture, It passes the energy to crankshaft through connecting rods, A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is

Figure 5 Piston in an IC Engine

made gas-tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod.

5. Piston Ring(s): 

  

In a piston, there are two types of rings namely the compression ring and the oil control ring. The compression ring is sub divided into two: (i) top compression ring, and (ii) second compression ring, Thus a piston consists of three rings, named in order: top compression ring, second compression ring and oil control ring, The top and second compression rings forms a compact barrier against the air-fuel mixture i.e. not to leak it from the cylinder, The oil control ring serves two functions. Firstly, it lubricates the cylinder wall and secondly it provides lubrication between the piston and cylinder wall. Hence reducing the probability of ‘wear and tear’ ensuring durability of components.

Figure 6 Piston Rings (Compression & Oil Control)

6. Connecting Rod:    

It is also known as a ‘Piston Rod’, In a reciprocating engine, basically it connects the Figure 7 Connecting Rod piston to the crankshaft, Together with the crank, they form a simple mechanism that converts reciprocating motion into rotary motion, A connecting rod is always ‘Rigid’ in nature.

7. Crankshaft:  

Simply also known as a ‘crank’ is basically one component which is casted, It is attached with the connecting rod, which converts ‘to-and-fro’ motion into rotary motion,

Figure 8 Crankshaft

8. Cam-shaft: 



In internal combustion engines with pistons, the camshaft is used to operate poppet valves. It then consists of a cylindrical rod running the length of the cylinder bank with a number of oblong lobes protruding from it, one for each valve. The cam lobes force the valves open by pressing on the valve, or on some intermediate mechanism as they rotate, Shaft in engine contains series of cams ( ) for operating the engine value mechanism and is driven by gears/timing belt/sprocket/chain.

Figure 9 Cam-shaft

9. Spark Plug:   

 

It produces a high spark upon high voltage, Burns up the air-fuel mixture, A spark plug is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine Figure 10 Spark Plug to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the engine, A spark plug has a metal threaded shell, electrically isolated from a central electrode by a porcelain insulator. The central electrode, which may contain a resistor, is connected by a heavily insulated wire to the output terminal of an ignition coil or magneto, The spark plug's metal shell is screwed into the engine's cylinder head and thus electrically grounded.

10. Dip Stick:  

A dipstick is one of several measuring devices, In a car or an IC Engine, a dipstick is used to measure the level of motor oil.

11. Water Pump:  

Generally, it is of centrifugal type, Its purpose is to circulate water mainly for purpose of cooling of an IC Engine.

Figure 11 Dipstick

Figure 12 Water Pump

12. Oil Pump:  

Its purpose is to circulate oil (engine oil) under high pressure when the engine is running, It lubricates some components of an IC engine such as bearings and thus assists in cooling, Figure 13 Oil Pump

13. Fly Wheel:    

Rotary Mechanical device that stores Mechanical Energy, It also has enough moment of inertia for continual mechanical processes to take place resisting any change in rotational speed, It provides continuous energy when energy source is disconnected, Fly wheels are made up of steel and rotate on conventional bearings. Figure 14 Fly Wheel

14. Manifold: 

It means ‘many folds’,

 

The intake manifold (blue colour) air-fuel mixture evenly to all cylinders, The exhaust manifold (red colour) collects exhausts from all the engine and exhausts it through one pipe.

Figure 15 Manifold

15. Engine Valves:   

These are located in the cylinder head, Its purpose is to take in air-fuel mixture and exhaust it upon burning, Engine valves are of two types: Type – I (Intake) and Type – II (Exhaust).

Figure 16 Engine Valves

16. Oil Pan:  

An ‘oil pan’ can be described as a source and sink for fuel, Here all of the engine oil stays when engine is in idle condition.

Figure 17 Oil Pan

17. Piston Pin:  

Also known as GUDGEON PIN, Its function is to connect the piston rod to the piston.

Figure 18 Gudgeon Pin

18. Alternator:  

We can state that Alternator in general sense is a motor, It converts Mechanical Energy into Electrical Energy using a rotatory magnetic field with a stationary armature.

Figure 19 Alternator

Conclusion: In this laboratory assessment, we were made familiar with the functions of various components of an IC Engine. Its manufactory materials, functions and purposes....