CVHF Presentation_Basic Operation

7/22/2019 CVHF Presentation_Basic Operation

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Familiarization and Basic Operation of CVHF Chiller

Date


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TOPICSTOPICS

Overview

Typical View

Refrigeration System Operating Principle

u r ca on o or oo ng ys em

Purge System

Chiller Control System a n enance

Questions

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OverviewOverview

CVHF Feature

> Single compressor, CENTRIFUGAL type water cooled liquid chillers

> Uses R-123 as refrigerant and Trane Oil 0022

Model Number Coding System

CVH F 049 D A 2 P 0 L C N 2 7 1 8 W B E 8 R B C00

Digits

1,2 CV Unit type Centravac Hermetic 14 C Control Interface, UCP3

3 H Drive Type, Direct Driv 15 N Comp KW, CPKW

, , ,

5,6.7 049 Nominal Tonnage,770Ton Comp Impeller Cutback

Design tons 751.75 1st 2nd

8 D Voltage, 460/60/3 27.6 27.6

9 A Unit type, Cooling Condenser

10,11 2P Design Sequence 19 8 Evap Shell Size, 080 long shel12 0 Hotgas bypass, without 20 W Evap tube bundle size,800 Nom

13 L Purge Purifier

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Typical View of a CVHF ChillerTypical View of a CVHF Chiller

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Major Components of the Chil lerMajor Components of the Chil ler

Compressor It is the heart of the vapor compression system. It provides the pressure increase necessary to facilitate the

transfer of heat.

Condenser

Meterin Device

It receives superheated refrigerant from the compressor andremoves the superheat and liquefy the refrigerant (sub cooling).

Evaporator

refrigerant to the evaporator.

It transfer heat from a substance being cooled to a boilingrefri erant.

It is a devices intended to reduce energy consumption, or toerform another useful function like reheatin a fluid.

Purge The purgeis designed to remove non-condensable gases andwater from the refrigeration system.

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Refri eration S stemRefri eration S stem

, ,

personnel spaces. The systems do this with refrigerantsthat remove heat from the heat source and discharge it

to a heat sink.

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Basic RefrigerationBasic RefrigerationCycleCycle

Cooling

Tower

Superheated vaporSub-cooled liquid

CONDENSER 23

Metering

DeviceCOMPRESSOR

EVAPORATOR 14

LP Vapor l ine

Saturated vaporMixture

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COOLHEAT


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OPERATING PRINCIPLESOPERATING PRINCIPLES

Evaporator Componentstube bundletube bundle

liquidliquidrefrigerantrefrigerant

chilledchilled

waterwaterreturnreturn

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orifice systemorifice system


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CENTRIFUGAL COMPRESSOR COMPONENTSCENTRIFUGAL COMPRESSOR COMPONENTS

Inlet Guide Vanes Impellers

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Inlet Guide Vanes

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Condenser

95

Condenser

85

1

Water In

De-su erheats and Condenses Refri erant

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1

Vapor


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Metering Orif ice

The Metering Orifice MetersRefrigerant Flow

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CVHF Refrigeration Cycle with EconomizerCVHF Refrigeration Cycle with Economizer

2-Stage Refrigerant Flow

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ONOMIZ R

o n a ge

Elim inator

Orifice

FromCondenser

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CVHF Refrigeration CycleCVHF Refrigeration Cycle

2-Stage P-H Diagram

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Efficiency


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General Assembly Oil/Refrigeration System Schematic

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Purge SystemPurge SystemPurge SystemPurge System

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Refrigerant ReportRefrigerant Report

Purge Operating ModesPurge Operating Modes(Stop, On, Auto, Adaptive)

Purge Operating ModesPurge Operating Modes(Stop, On, Auto, Adaptive)

1. Sto The ur e condensin unit will not1. Sto The ur e condensin unit will notrun.

2. On - The purge condensing unit runs

run.

2. On - The purge condensing unit runs

operational status.

3. Auto - the purge condensing unit runs when

operational status.

3. Auto - the purge condensing unit runs when

4. Adaptive The purge condensing unitoperation is totally dependent on past purge

4. Adaptive The purge condensing unitoperation is totally dependent on past purge

activity. Purge monitors its 1.) daily pumpouttime with the chi ller ON or OFF, over the last 24

hours and 2.) average daily pumpout time with

the chil ler ON or OFF, over the last 7days.

activity. Purge monitors its 1.) daily pumpouttime with the chi ller ON or OFF, over the last 24

hours and 2.) average daily pumpout time with

the chil ler ON or OFF, over the last 7days.

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Advantages of Adaptive ModeAdvantages of Adaptive Mode

Objectives of operating the unit in the AdaptiveObjectives of operating the unit in the Adaptive

Operating the purge refrigeration circuit to effectively

accumulate non-condensables with or without the

Operating the purge refrigeration circuit to effectively

accumulate non-condensables with or without the

c er runn ng.

Provide information to the operator as to whether

leakage is on the high-pressure or low-pressure side of

c er runn ng.

Provide information to the operator as to whether

leakage is on the high-pressure or low-pressure side of.

Decrease energy usage by running the purge

refrigeration c ircuit only when needed to remove non-

.

Decrease energy usage by running the purge

refrigeration c ircuit only when needed to remove non-

, ., .

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Purge SystemPurge System

RR--404a Condensing Unit404a Condensing UnitRR--404a Condensing Unit404a Condensing Unit

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System ContaminationSystem ContaminationSystem ContaminationSystem Contamination

Equipment LeaksEquipment Leaks

Poor EvacuationPoor Evacuation

Introducing Contaminated RefrigerantIntroducing Contaminated Refrigerant

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Earthwise Purge SystemEarthwise Purge System

Condensing Unit

Condenser

Expansion

CompressorCarbon Tank

Temp Sensor

Exhaust

Pressure ReliefDevice

Device

Com ressor Suction

PumpoutSolenoid Valve

To Chiller

Vent Line

Solenoid ValveRestrictor

To Chiller

Purge

Tank

Temp Sensor Pump-out

Compressor

RegenerationSolenoid Valve

Isolation

Evaporator

Carbon

TankHeater

Finned

Heater Well

a ve

FloatSwitch

Liquid Drain

Line

apor

Pick-up Line

Filter/DrierChiller

Condenser

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Valves


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Purge Condenser RPurge Condenser R--404a Circuit404a CircuitPurge Condenser RPurge Condenser R--404a Circuit404a Circuit

CONDENSER

R-404a EVAP

COMPRESSOR 85 F LIQUID

TEMP SENSOR -16 F LIQUID

> 60 F Vapor

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AEV-

INLETR-123

OUTLET

R-123

OUTLET

75 F LIQUID


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No Air in purge tankNo Air in purge tank

-Mixture from EXV (-16 o F)

Purge coi l area availablefor superheating

R404a Gas tocondensingunit Chiller refrigerant

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suction (90 F)


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Air of Purge TankAir of Purge Tank

R404a Liquid/Vapor Mixture from

EXV (-16F)

Purge coil area

available for Air

superheating

Chiller refrigerant vapor (100F)

R404a Gas to Condensing

Unit compressor Suction

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Air fills Purge TankAir fills Purge Tank

R404a Liquid/Vapor Mixture from

EXV (-16F)

No coil area

available for

superheating

R404a Gas to condensing unit

compressor Suction (-16F)

Air

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onon-- on ensa e emovaon ensa e emova

When sufficient non-condensable have accumulated in the purge tank to

decrease the compressor suction temperature below the pump out initiateset point a pump out cycle has begun. The cycle will be terminated when the

compressor suction temperature sensor increases above the pump out

terminate set-point.

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Control SystemControl System

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MaintenanceMaintenance

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Maintenance

After the first 6 months or 1000 hours operation, whichever comes first, it is

recommended to change the oil and filter. After this oil change,

recommendations are to subscribe to an annual oil analysis program rather

than automatically change the oil as part of scheduled maintenance.

Proper Water TreatmentThe use of untreated or improperly treated water in a CenTraVac may result

in scaling, erosion, corrosion, algae or slime. It is recommended that the

services of a qualified water treatment specialist be engaged to determine

equipment failures which result from untreated or improperly treated water, orsaline or brackish water.

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Basic Maintenance ItemsBasic Maintenance Items

Daily

Monitorin of Chiller Re uired Parameters

Oil Level visual check (using sight glass)

Quarterly

Cleaning of water strainers (Piping)

Semi-Annually

Lubrication of Vane Control System (bearings, ball joints,...)

Annually a rat on o ontro s re ays, sensors,

Measure Compressor Motor Winding resistance

Oil Change and Oil Analysis

Other Maintenance Requirements

Inspect and clean condenser tubes if necessary

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Compressor Motor ProblemCompressor Motor Problem

Voltage And Current Unbalance

100 X the Sum of the Deviation of the Voltages, (Currents),

v e y e verage

The Unbalance Should Not Exceed 2% Voltage or 10 % Current

Example:

Measured Voltages :

480 Volts

Sum of the Deviation:

480 - 470 = 10

470 Volts460 VoltsAverage: = 470 Volts

-

470 - 460 = 1020 X 100 = 2,000

, : = .

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Other Important ItemsOther Important Items

CAUSES OF SURGE

Too hi h condensin tem erature

Too much incondensable in a low pressure unit :

don't operate unit at full load if purge unit is not stabilized ( pay attention

to leaks of refrigerant through purge unit )

Cooling tower temperature too high :

too much refrigerant

dirty tubes too low water flow rate

Lack of refrigerant

too long part load operation

un m g surge ur ng a ong me a par oa o , s en

recommended to reduce condenser inlet water temperature of 1F per

10% load reduction

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Other Important ItemsOther Important Items

CAUSES OF SURGE SURGE CONSE UENCES

Liquid refrigerant carry over

Loss of performance

too high evaporator water

temperature

Oil carr over

Amperage peaks

Vibrations and noise

noisy compressor

amperage fluctuations

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Normal ParametersNormal Parameters

Normal Operating Conditions

Description Condition

vapora or ressure o g acuum

Condenser Pressure 0 to 10 psigOil Sump Temperature

Unit Not Runnin 140 to 145F

Unit Running 62 to 162F

Differential Oil Pressure 18 to 22 psid

Discharge Oil Pressure 7 to 15 psig

Condenser Approach Temp = Sat Cond Temp - Lvg Cond Water Temp

Evaporator Approach Temp = Lvg CHW Temp - Sat Evap Temp

Notes: 1. ARI Conditions are: cond water - 85F & 3 gpm/xxx tons

Evaporator Water: 54 to 44F2. Condenser pressure is dependent on condenser water temp and

should equal the saturation pressure of HCFC-123 at a temp above that of leaving

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.

3. Std. Cond App Temp: 0 to 5F ; Std Evap App Temp: 0 to 4F


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QuestionsQuestions

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an youan you

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CVHF Presentation_Basic Operation