Dual Cycle

Presented By:

ITM UNIVERSE

Name Enrollment No.Harshal Bhatt 150950119504Chintan Dave 150950119507Vaibhavraj Chavda 150950119508Smeet Gandhi 150950119511

Oil Engine 1888. Ackroyd Staurt (Automatic Ignition).Rudolf Diesel Used This Principle And

Developed Basis Of Dual Combustion Engine.

History

Dual cycle was first introduced by an engineer named Gustav Trinkler . In this cycle , part of the heat addition is at constant volume( Isochoric ) and at constant pressure ( Isobaric ) . The name Dual cycle is derived from the fact that if is an integration of both the Otto and Diesel cycle.

History

Comparison Between Otto, Diesel and Dual Cycle

AirTC

BC

CompressionProcess

Const pressure

heat additionProcess

ExpansionProcess

Const volume

heat rejectionProcess

Const volume

heat additionProcess

Qin QoutQin

Dual Cycle

Process 1 2 Isentropic compressionProcess 2 X Constant volume heat additionProcess X 3 Constant pressure heat additionProcess 3 4 Isentropic expansionProcess 4 1 Constant volume heat rejection

Qin

Qin

Qout

Dual Cycle

It is an internal combustion four stroke engine.

“Dual” Because Combustion Takes Place In Two Parts First At Constant Pressure And Second At Constant Volume.

This makes it better than diesel engine’s cycle.

Dual Combustion Engine

Also Known As The Limited Pressure Or Mixed Cycle, Seiliger Cycle Or Sabathe Cycle.

Thermal Cycle That Is A Combination Of The Otto Cycle And The Diesel Cycle.

Dual Combustion Cycle

It is a four stroke engine.Improved and modern

form of old Diesel engine’s cycles.

Its one stroke is divided into two parts allowing it to carry out more work..

Have increased efficiency.

Characteristics

Parts Of Engine

Each Cycle Of Piston Consists Of Two Opposite Motions:

There Is A Motion In One Direction, And Then A Motion Back In The Opposite Direction. Each Of These Is Called A Stroke

Stroke Is The Action Of A Piston Travelling The Full Length Of Its Locomotive Cylinder Or Engine Cylinder In One Direction. 

Stroke

The dual cycle consists of following operations: Adiabatic compression Addition of heat at constant volume. Addition of heat at constant pressure. Adiabatic expansion. Rejection of heat at constant volume.

Sequence of Operations

Engine efficiency of thermal engines is the relationship between the total energy contained in the fuel, and the amount of energy used to perform useful work.

Efficiency

From first law of thermodynamics

Q = ∆U + WAnd.. ∆W = Q1 – Q2

The efficiency of engine is defined as ƞ = Output / input

Expression For Efficiency

Continued..The efficiency of engine is defined as useful

work done to the heat provided.

Where, Q1 is the heat absorbed Q1 – Q2 is work done.

The analysis of cycle is as follows:

The heat is supplied In two stages. hence Qin = mcp(T4 – T3) + mcv(T3 – T2)

The heat rejected is Qout = mcv(T5 – T1)

Efficiency of dual combustion engine

The thermal efficiency may be found as follows: ƞ = 1 – Qout/ Qin

= 1 – mcv(T5 – T1)/ mcv(T3 -T2)+mcp(T4 – T3)

=1 – (T5 – T1)/ (T3 – T2) +ϒ(T4 – T3)

Simplification

Dual combustion engines are most commonly used for mobile propulsion in vehicles and portable machinery.

In mobile equipment, dual combustion is advantageous since it can provide high power-to-weight ratios.

Applications

Generally using fossil fuel(mainly petroleum), these engines have appeared in transport in almost all vehicles (automobiles, trucks, motorcycles, boats, and in a wide variety of aircraft and locomotives).

Automobile

Very high power-to-weight ratios are required, dual combustion engines appear in the form of gas turbines. These applications include jet aircraft, helicopters, large ships and electric generators.

Generators/Aircrafts

Marine Engines

There is a role for Dual Combustion engines for future energy use, because– Dual combustion engine has high power to weigh ratio.– Relatively low cost.– Flexible fuel use.– Established manufacturing investment.

Future Energy Use

Work Example 1

SOLUTION

The End

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