Mr S K Deshmukh

7/28/2019 Mr S K Deshmukh

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1KIRLOSKAR PNEUMATIC CO. LTD.

Presentation on,

DEVELOPMENTS IN RECIPROCATINGCOMPRESSOR

S. K. Deshmukh

DGM-ACD (R & E)

9/12/2008


Back Ground

1940s Low speed 180 rpm, f irst generation of reciprocating

compressors developed

In last 10 y ears, predictions were made that Recip will be tapered

down.

However, Recip compressors hav e ov ercome the past concerns ofcertain weaknesses through technological advancements.

It is a f av ored selection by all industries General purpose, Power, Oil,

Gas, Petrochemical and Air separation etc.

It can handle v irtually all gases and do compression from v acuum to

3500 bar (Hy per compressor f or LDPE ethy lene) with power rating up

to 30 MW of single compressor.


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Reciprocating Compressor Advancements

(Latest Design Features)

a) Valve design f or low noise (environment f riendly ) & high energy

eff iciency (low v alv e losses)

b) Piston ring materials Lif e enhancements & low friction

c) Synthetic lubricants Bio degradable - env ironment f riendly.

d) Condition monitoring for health of Compressor web based

e) Digital Pulsation analysis

f) High speed designs

g) Air cooled packages

h) Integrated packages

i) Engine driven direct coupled high speed compressorj) Uncooled cy linder f or gases of lower adi abatic exponents (Jacketless)


Reciprocating Compressor Advancements(Latest Design Features)

k) Special Metallurgy compatible f or gases inv olv ed

l) Life enhancements

m) Use of jacket & intercooler / aftercooler heat f or building heating as

low grade heat

n) Compact design (Low weight to capacity ratios energy packed

machines )

o) Env ironmentally f riendly materials f or construction i.e. Asbestos free

p) Use of recy clable materials

q) High pressure engineered compressors

r) Conf ormance to the international standards such as API618, API 11P

etc.

s) Electricals & Instrumentation: Suitable f or specif ied area classif ication

/ Gas group / Temperature Class

t) Integrated Engine Compressor.


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Reciprocating Compressor Advancements

(Latest Design Features)u) Env ironmental Awareness : EMS (ISO 14001) & OHSAS 18001- ref lecting in

design specif ications e.g. compliance to Bharat Stage II I (Euro 3),

Residential type silencers, Spark Arrestor (I.S. specif ied)

v ) Saf eties compliance (e.g. API RP-520 / API 526 / API 527), CCOE approv ed

cy linders etc.

w) Use of Computational Fluid Dy namics (CFD), Finite Element Analysis (FEA),

Thermal / Thermody namic Simulation study etc.

x) Use of Energy Eff icient Motors matching with National Electric Manufacturers

Association's (NEMA's) MG1-1993 publicat ion / BIS 12615.

y ) VFD f or v ariable demand cycles and multiple units installations.

z) Silenced versions Canopy f or noise lev el of 75 dB.


Compressor suction & Discharge Valves play important role of

heart of Compressor

Important components

a) Valve seats

b) Valve guard

c) Mov ing / sealing element Valve plate , channel etc.

d) Springs / cushion plates

Valve Design Enhancing the Valve Life &Reliability


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Valve Design Valve Dynamics



Use of material adv ancements such as PEEK.

Design criterion for optimization (Characteristics of Ideal valv e)

a) The minimum clearance v olume.

b) Low impact v elocity (low lif t).

c) The largest possible f low area & f low coeff icient.

d) Light weight combined with low lif t with quick act ion.

e) Robust construction f or long lif e.

f ) Low price.


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Torsional Vibration Analysis

The natural f requencies of torsional v ibration of the idealized complete

drives train system comprising of motor, coupling, and compressor

calculated using Torsional Critical Speed computer program.

The equiv alent mass elastic diagram f or the complete driv es train will be

used in determination of torsional (mechanical) natura l f requencies / critical

speeds where a potential f or resonant behav ior exists.

Interference / Campbell Diagram developed to identify & av oid harmf ul

resonant behav ior f or the operating speed range.

Determination of v ibratory torque & stresses on the components of the

drive t rain to ensure such torque & stresses v ariations are within the saf e

limits of the components with adequate separation margin as per API

Standard 618.


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Torsional Vibration Analysis


Compressor Design PhilosophyCompressor Design Philosophy

Utilization of s tandards, serv ice proven designs components and with

indiv idual compressor designed to cater to precise needs

Lube oil sy stem, Pulsation dampeners, Saf eties, Instrumentation and

Controls as per API-618 with minor deviations

Gas Cooler designs generally per TEMA R / B and also as per API-660& API-661

Pressure Vessel design as per ASME section-VIII

15 Years of serv ice lif e and 2 Years without a major ov erhaul.

ARM Theme

Av ailability , Reliability & MaintainabilityAv ailability , Reliability & Maintainability


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Compressor Packages

A wide range of auxiliary equipment on Process gas compressor

packages includes:

Forced lubrication systems and waterconsoles comply ing with

API -618 standards.

Capacity control systems including suction v alv e unloaders,

v olume clearance pockets (manually or pneumatically operated),

automatic by -pass sys tems and step less capacity control sy stems.

Pulsation dampeners designed to attenuate pressure pulsations in

process pipe work.

Digital and Analogue computer analysis of the acoustic and

mechanical interaction of t he v essels and associated piping sy stems.

Gas intercoolers and aftercoolers of shell and tube, air blast,

plate type or other design.


Natural Gas Compressor


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Advancements in Pulsation Control Technology

Department of Energy (DOE) and the Gas Machinery Research Council

(GMRC) spo nsored program terme d as the Advanced Reciprocating

Compressor technology (ARCT) program.

Necessity of Advanced Pulsation Control technique due to high speed of

compressor with high horse power requirements.

This design tool leads to

a) Filtering pulsations.

b) Reduced equipment, piping v ibrations & noise.

c) Increased sy stem reliability.

d) Improved compressor eff iciency .

e) Enhancing compressor v alv e lif e. Design approaches 1, 2 or 3 as per API 618 used as per applications

The rapid advancements of digital computer aided Design Systems

enables to analyze the f luid dy namics to predict attenuation

characteristics, pass bands, pulsation lev els, acoustic simulation etc.

Simple solutions giv e substantial power consumption sav ing.


Advancements in Pulsation Control Technology


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Inertia Balanced with Zero Couple BOPs

Latest Balanced Opposed Compressor v ersions are prov ided with

crankshaf ts with zeroing couple feature wherein crank throws are exactly

aligned thereby eliminating most v ibrations generally associated with

reciprocating ty pe compressors.

Inertia f orces balanced within 1%

Enables use in v ibration sensitiv e application such as off shore platf orms

and trailer mounted units.

Permits the compressor to run at high speed of 1800 rpm


Truck Mounted High Pressure ReciprocatingCompressor (200 Bar) - ONGC


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CNG Packages


Advantages of Natural Gas Driven Air Compressors

Natural gas engine-driven air compressors offer many

potential benefits, inc luding:

Lower cost of producing compressed air

Lower cost for providing steam and hot water for heating or

cooling needs

Lower life-cycle cost

Attractive return on i nvestment

Lower cost of emergency backup power equipment

Secured capability for supplying compressed air during

power disruptions


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Focus on Life Enhancement

Fig. Primary causes of unscheduled reciprocating compressor shutdowns


From Concept ( 3-D) to Manufacturing (2-D Drawing)


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Design optimisation for weight reduction

(Resultant Deformation plot)


Effective visualization(Compresso r House )


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Energy Efficient Motors

Energy-eff icient motors, also called premium or high- eff iciency motors or

EFF1, are 2 to 8% more eff icient than standard motors.

Motors qualify as "energy-eff icient" if they meet or exceed the efficiency lev els

listed in the National Electric Manuf acturers Association's (NEMA's) MG1-1993

publication.

Energy-eff icient motors generally have longer insulation and bearing lives,

lower heat output, and less v ibration.

In addition, these motors are of ten more tolerant of ov erload conditions andphase imbalance.

This results in low f ailure rates, which has prompted most manufacturers to

off er longer warranties f or their energy-eff icient lines.


Energy Efficient Motors

The ef f iciency of a motor sy stem depends on several f actors, including:

a) motor ef f ic iency

b) motor speed control

c ) proper s izing

d) power supply quality

e) distribution losses

f) mechanical transmission

g) maintenance practices

h) end-use mechanical eff iciency (pump, f an, compressor, etc).

The non-energy benefits of higher eff iciency sy stems are better process

control, reduced disruption and improved product quality .

Energy-eff icient motors should be considered for all new installations,

replaceme nt of failed motors, or as spares.


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VFD

VFD- VARIABLE SPEED DRIVE

The synchronous speed of an inducti on motor is d etermi ned by the following equation.

N s = 120 f / p ( rpm)

The only way to chang e th e speed, for a gi ven pole numb er is to vary th e freque ncy

VFD B ASIC PRINCIPLE -

The process of transfor mi ng the stable power line frequency i nto a variabl e

frequency i s basi cally done in two steps:

1. The sinusoi dal voltag e is rectifi ed into an DC voltage.

2. The DC vol tag e is chopped up to an DC vol tag e of the desired fr equency

VFD- VARIABLE SPEED DRIVE

By Providing VFD in compressor control we can vary th e C ompr essor R PM depending

on req uirement. This c ompl etely avoids unloading and saves unl oad powerconsumption which is n or mall y 25- 35% of the full l oad consumpti on.

Major advantage of variable speed drive is that i f 4 to 5 c ompr essor are connected

to a commo n header, then by i nstalling VFD in on e compressor, th e energ y savi ng due

to pr essure reduction is achieved i n all the compressor.

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Mr S K Deshmukh