“MAGNETIC LEVITATION TYPE COMPRESSORS FEASILSILITY ANALYSIS FOR HVAC APPLICATIONS”

December 2010

A PRELIMINARY PROJECT REPORT ON

“MAGNETIC LEVITATION TYPE COMPRESSORS FEASILSILITY ANALYSIS FOR HVAC APPLICATIONS”

Prepared by:

NAME ROLL NO.

1. PATEL DHARMESH D. 7436

2. PATEL NIMESH U. 7449

3. PATEL NIRAV B. 7451

4. PATEL TARANG P. 7462

Guided by:

Dr. SONAL DESAI

CKPCET.

C.K.PITHAWALA COLLEGE OF ENGINEERING AND TECHNOLOGY, SURAT.

YEAR: 2010-11

CERTIFICATE

This is to certify that Preliminary Project Report entitled “MAGNETIC LEVITATION TYPE COMPRESSORS FEASILSILITY ANALYSIS FOR HVAC APPLICATIONS”

Submitted by:

NAME ROLL NO.

1. PATEL DHARMESH D. 7436

2. PATEL NIMESH U. 7449

3. PATEL NIRAV B. 7451

4. PATEL TARANG P. 7462

For the partial fulfillment for the award of degree in Bachelor of Engineering in Mechanical

Engineering of C. K. PITHAWALLA COLLEGE OF ENGINEERING AND TECHNOLOGY,

SURAT (GUJARAT) is the report of their work carried out under my supervision and

guidance.

Guided By:

Dr. SONAL DESAI

Mech. Engineering Department,

C. K. Pithawalla College of Engineering

And Technology, Surat.

Head of Department,

Mechanical Engineering Department,

C.K.Pithawalla College of Engineering

And Technology, Surat.

CERTIFICATE OF ACCEPTANCE

This is to certify that Preliminary Project Report entitled “MAGNETIC LEVITATION TYPE COMPRESSORS FEASILSILITY ANALYSIS FOR HVAC APPLICATIONS”

Submitted by

NAME ROLL NO.

1. PATEL DHARMESH D. 7436

2. PATEL NIMESH U. 7449

3. PATEL NIRAV B. 7451

4. PATEL TARANG P. 7462

For the Partial fulfillment for the award of degree in Bachelor of Engineering in Mechanical

Engineering of C. K. PITHAWALLA COLLEGE OF ENGINEERING AND TECHNOLOGY,

SURAT (GUJARAT) is hereby approved.

Juries :

1. ___________________

2. ___________________

3. ____________________

ABSTRACT

In present work we are going to study magnetic levitation compressor as a possible

replacement of screw or centrifugal compressor in the field of refrigeration and air

conditioning. As a start of it we have tried to understand different types of compressor with

the help of purvi engineering which include study of different types of compressor installed

at various HVAC plants.

Active Magnetic Bearings (AMBs) have industrial interest in high-speed machinery

due to their advantages of no mechanical contact, no need for lubrication, high precision

operation, and ability to operate at high rotational speeds. An AMB levitates a rotor by

means of electro-magnetic forces at an equilibrium position at which all forces acting on the

rotor are balanced. The principle of active control is to measure the rotor position; any

deviation will influence the magnetic flux, which is then altered to control the rotor position.

Despite many inherent advantages, active magnetic bearings suffer from limited force

capacity.. This thesis details research undertaken to investigate the behavior of a rotor in an

AMB system when contact occurs with auxiliary bearings.

ACKNOWLEDGEMENT

We are highly grateful to people who helped us out with our project title study of

“MAGNETIC LEVITATION TYPE COMPRESSORS FEASILSILITY ANALYSIS FOR

HVAC APPLICATIONS” with due respect to our project guide Dr. SONAL DESAI without

whose help this work would not have been possible.

We also take this opportunity to thanks Mr. Nimish Shah, Managing Director & Mr. Ankit

Mody, Marketing Manager, Purvi Engineeriners Pvt. Ltd. Who supported us and provided us

the platform for working with their officials at the project site and all the employees of purvi

engineers who directly or indirectly helped us in completion of this Preliminary report.

.

INDEX

1. INTRODUCTION…………………………………………………1 1.1 CENTRIEUGAL COMPRESSOR ……………………………1

1.2 SCREW TYPE COMPRESSOR………………………………..3

1.3 MAGLEV COMPRESSOR……………………………………..4

2. MAGLEV COMPRESSOR……………………………………….52.1 WORKING OF MAGLEV COMPRESSOR…………………...5

3. LITERATURE REVIEW…………………………………………8

3.1 DEFINATION OF COMPRESSOR............................................83.2 ROLE OF COMPRESSOR IN HVAC PLANT………………...8 3.2.1 HISTORY OF REFRIGERENT…………………………..83.3COMPARISION OF CENTRIFUGAL TYPE COMPRESSOR

AND MAGLEV COMPRESSOR ……………………………....9

4. FUTURE SCOPE OF WORK……………………………………11

5. REFERENCES……………………………………………………12

LIST OF FIGURES

1.1 SECTIONAL VIEW OF CENTRIFUGAL COMPRESSOR……2

1.2 SECTIONAL VIEW OF SCREW TYPE COMPRESSOR……...3

2.1 MAGNETIC BEARINGS………………………………………….6

2.2 WORKING OF MAGLEV COMPRESSOR…………………......7

LIST OF TABLES

3.1 COMPERATION OF SCREW, CENTRIFUGAL AND

MAGLEV COMPRESSOR………………………………………10

NOMENCLATURE

COP = CO-EFFICIENT OF PERFORMANCE.

EER = ENERGY EFFICIENCY RATIO.

HVAC = HEATING VENTILATION AND AIR CONDITIONING.

CHAPTER: 1INTRODUCTION

Compressors are a device that compresses or increases the pressure on gas or air. As air is

compressible, the applied pressure helps to reduce the volume of existing air. Liquids are

comparatively incompressible, so the main act of a pump is to pressurize and transfer the

fluidthroughachannel.

Temperature always tends to rise if compression ratio is increased. Considering this fact,

compressions are designed to perform on per stage basis and concurrently cooling the

gas.

There are different types of Compressor ranging from the simple hand pump and the

piston-equipped compressor. Each compressor achieve different compression ratio &

varies in horsepower. Some compressors require oil to operate and some do not. Different

types of compressors are Centrifugal compressors, mixed-flow compressors, Axial-flow

compressors, Reciprocating compressors, Rotary screw compressors, Rotary vane

compressors, Scroll compressors, Diaphragm compressors, etc.

1.1 CENTRIFUGAL COMPRESSOR.

Centrifugal Compressors are used for continuous & stationary services in industries such

as oil refineries, chemical and petrochemical plants and natural gas processing plants.

Their application can be from 100 horsepower to thousands of horsepower. Centrifugal

compressors are used in small gas turbine engines or as the final compression stage of

medium sized gas turbines.

Centrifugal compressors are suitable for low specific speed, high pressure ratio and low

mass flow application.

The flow field of in an impeller passage of a centrifugal compressor is highly complex,

three dimensional an unsteady.

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The   centrifugal   force   utilized   by   the centrifugal  compressor  is  the  same  force

utilized by the centrifugal pump.

In this type of compressor the impeller rotates against the casing of the compressor

The air become Compressed more And more is thrown out to casing by impeller blades.

The pressure of air is increased as it pushed along the path A,B,C, which is shown in fig.

Fig. 1.1 Sectional view of Centrifugal compressor

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1.2 SCREW TYPE COMPRESSOR.

Rotary Screw Compressor is a type of gas compressor that uses two meshed rotating

positive-displacement helical screws to force the gas into a smaller space. These are

usually used for continuous operation in commercial and industrial applications and may

be either stationary or portable. Their application can be from 3 horsepower (2.2 kW) to

over 1,200 horsepower (890 kW).

Screw compressors are rotating machines that transform the mechanical work performed

by electric motors, turbines or IC engines into potential energy of gas, vapor or multi-

phase mixture by reducing its volume and thereby raising its pressure.

The screw type of air compressor is an oil-injected, helical screw, direct drive, positive

displacement air compressor. It may be single or dual stage.

Male RotorLobe

Discharge(Bottom)

FemaleRotorFlute

Suction

Suction

Discharge

Fig.1.2 Sectional view of Screw type compressor.

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Figure 1.2 shows the basic geometry of the rotary screw compressor. It is a simple

representation of the actual rotors. We have labeled the male rotor lobe and the female rotor

flute. As the rotors turn in an outward direction, the male flute will unmesh from the female

flute forming an area for the gas to enter.

The gas becomes trapped in the machine and compression occurs when the lobes of the

rotors begin to mesh together again. The shaded area represents the pocket of gas that occurs

within a specific flute. Another fig. is a representation of the side view of the machine. The

same flute is shaded for comparison. Here we see the suction port in the upper left corner and

the discharge port in the lower right corner. The rotors will turn in an outward direction

forcing the male and female flutes to unmesh, allowing process gas to enter the top of the

machine.

1.3 MAGLEV COMPRESSOR.

A magnetic bearing is a bearing which supports a load using magnetic levitation. Magnetic

bearings support moving machinery without physical contact, for example, they can levitate a

rotating shaft and permit relative motion with very low friction and no mechanical wear.

They are in service in such industrial applications as electric power generation, petroleum

refining, machine tool operation and natural gas pipelines.

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CHAPTER: 2

Magnetic Levitation Compressor

2.1 Working of Magnetic Levitation Compressor

Magnetic Levitation Compressor uses a technology similar to that of magnetic-levitation (maglev) trains. Magnetic fields levitate the compressor shaft so that it needs no mechanical bearings.

Magnetic Levitation Compressor there are uses magnetic bearings, which avoid the oil

issues and reduce some of the power consumption because there is no mechanical friction

no oil is needed, for lubrication. Thus, the oil-management system used by other types of

compressors is eliminated. The frictionless compressor shaft is the compressor’s only

moving component, and it rotates on a levitated magnetic cushion.

If the magnetic bearings fail, the back-up bearings prevent a compressor failure. One axial and two radial magnetic bearings hold the shaft in position.

When the magnetic bearings are energized, the motor and impellers become levitated in

mid-air.

A very small amount of oil is lubricating the other system components, such as seals and

valves, and often even this small amount of oil is not needed.

When the compressor is not running, the shaft assembly rests on graphite-lined, radially

located touchdown bearings.

The magnetic bearings normally prevent contact between the rotor and other metallic

surfaces.

Multiple Maglev compressors mounted on a common shell so require less space.

Maintenance routines are simplified and easily completed without system shutdowns.

Individual compressors can be shut down for maintenance without requiring the entire

system to go off line.

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Fig 2.1 MAGNETIC BEARING

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Fig 2.2 Sectional view of Maglev compressor

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CHAPTER: 3.

LITERATURE REVIEW

3.1 Defination of a Compressor.

A device used for pumping compressible fluids i.e, air, gas & steam is known as compressor.

It can be Rotary screw compressor, Centrifugal compressor, Magnetic levitation compressor

3.2 Role of compressor in HVAC plant

Compressors are the heart of Refrigeration system.

The compressor increases the refrigerant pressure about five to ten times. This increases the

temperature so heat can leave the refrigerant in the condenser.

Compressors are vapour pumps which is responsible for lowering the pressure on suction

side of the system and also responsible for increasing the pressure on the discharge side of

the system.

3.3 History of Refrigerant

The first air conditioners and refrigerators employed toxic or flammable gases like ammonia,

methyl chloride and propane, which could result in fatal accidents when they leaked. Thomas

Midgley, Jr. created the first chlorofluorocarbon gas, Freon, in 1928. The refrigerant was

much safer for humans but was later claimed to be harmful to the atmosphere's ozone layer.

Freon is a trademark name of DuPont for any chlorofluorocarbon (CFC), hydrogenated CFC

(HCFC), or hydrofluorocarbon (HFC) refrigerant, the name of each including a number

indicating molecular composition (R-11, R-12, R-22, R-134A). The blend most used in

direct-expansion home and building comfort cooling is an HCFC known as R-22. It is to be

phased out for use in new equipment by 2010 and completely discontinued by 2020. R-12

was the most common blend used in automobiles in the United States until 1994 when most

changed to R-134A. R-11 and R-12 are no longer manufactured in the United States, the only

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source for purchase being the cleaned and purified gas recovered from other air conditioner

systems. Several non-ozone depleting refrigerants have been developed as alternatives,

including R-410A, known by the brand name Puron. The most common ozone-depleting

refrigerants are R-22, R-11 and R-123.

Innovation in air conditioning technologies continues, with much recent emphasis placed on

energy efficiency and improving indoor air quality. As an alternative to conventional

refrigerants, natural alternatives like CO2 (R-744) have been proposed.

The increase in use of air conditioning over the years has been implicated as a

contributor to increasing obesity, because appetite naturally decreases in uncomfortably high

temperatures

3.3 Comparison of Centrifugal type compressor and Magnetic levitation type compressor.

Anti-friction bearings used in Screw & Centrifugal compressor so these have

limited life where as Magnetic Levitation compressor uses non-frictional (magnetic

bearing) so life is more.

Magnetic Levitation compressor has an extremely low startup in-rush current: less

than five amps, compared to 500 to 600 amps for a traditional screw compressor with a

cross-the-line starter.

Magnetic levitation compressor permits both weight and dimension reduction of

the units with respect to Centrifugal/screw compressors, allowing simplified site

operation

Unbeatable efficiency at part load, extremely silent operation make Mag-lev compressor

better than others.

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For Maglev compressor maintenance costs, noise, and vibration are all reduced compared

to other compressors.

For screw & Centrifugal compressor Lubrication is require but in Mag-lev compressor no

lubrication require.

In Maglev compressor Wear is less than others.

A Maglev compressor’s weight is one-third of what a conventional compressor of similar

capacity would be.

Screw Centrifugal Maglev

EER 2.98 3.08 17

COP 3.52 6.5 4

POWER CONSUMPTION(KW) 250 220 145

WEIGHT (Kg) 5525 1380 2390

PRESSURE (BAR) 9 3.6 15

ROTOR SPEED (RPM) About 10,000 2000 40,000

Maglev compressor’s requires significantly less material and energy to manufacture a

Mag-Lev compressor, adding positively to carbon footprint reduction process so it is less

costly than others.

Table 3.1 Comparison between Screw, Centrifugal & Maglev compressors

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CHAPTER: 4

Future scope of work

As understood from the global & national data available from HVAC industry, The demand

of Refrigeration & Air conditioning is increasing day by day. So to meet the never ending

need of cooling in HVAC industries high efficiency parts like compressors, cooling towers,

pumps are required. Since years Screw & Centrifugal Compressor are used to meet the

requirements of HVAC industry. It is planned to compare different type of compressors with

Magnetic levitation compressor from initial cost, running cost, maintenance and future point

of view for new installation as well as replacement in existing one.

Surat has few installation of Magnetic levitation based Compressors, some of them out of

Ramkrishna Export, Shivalik Westurn etc. Hence it is planned to compare technical data of

different types of compressors used in Refrigerant and AC plant.

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CHAPTER: 5

REFERENCES:

1. .http://www.climaveneta.pl/images/stories/Produkty/Climaveneta/Broszury/Agregaty/Climaveneta_TECS.pdf

2. .http://www.climaveneta.pl/images/stories/Produkty/Climaveneta/Broszury/Agregaty/Climaveneta_TECS.pdf

3. http://www.magnetal.se/Dokument/PhDThesis.pdf

4. http://scholar.lib.vt.edu/theses/available/etd-07052000-14530020/unrestricted/chapter1.pdf

5. http://www.york.com/products/esg/updates/eng-Updates/26.pdf

6. Jayawant, B.V., Electromagnetic levitation and suspension techniques, Edward Arnold, London, 1981.Wei, R.; Sun, G. & Liu, Y., The development status and future prospects of Maglev Technology, MAGLEV’2006 - 19th International Conference on Magnetically Levitated Systems and Linear Drives, Dresden, Germany, 2006.

7. Nissen, G., Current status of Maglev development programme, MAGLEV’2006 - 19th

International Conference on Magnetically Levitated Systems and Linear Drives, Dresden, Germany, 2006.

8. Budell, R. & Bus, W., Transrapid Maglev projects in the U.S.A., MAGLEV’2006 - 19th International Conference on Magnetically Levitated Systems and Linear Drives, Dresden, Germany, 2006.

9. Neumann, B., Utilisation of the TRANSRAPID in Europe, MAGLEV’2006 - 19thInternational Conference on Magnetically Levitated Systems and Linear Drives, Dresden, Germany, 2006.

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