Low Charge Ammonia Systems charge ammonia systems.pdfLow Charge Ammonia Systems BY RAMESH PARANJPEY...

Low Charge Ammonia Systems

BY

RAMESH PARANJPEY

ASHRAE FELLOW LIFE MEMBER

CHAIRMAN ISHRAE REFRIGERATION TECHNICAL GROUP

CELL PHONE : 98223 98220

MAIL ID: [email protected]

Website : http://Ramesh-paranjpey.com

mailto:[email protected]

OVERVIEW

Sr. No. Content

1. History

2. Reason to consider NH3

3. Norms and Standards

4. Recent development in NH3 Systems

5. Challenges

6. Conclusion

Reasons for Considering Alternatives

1. MONTREAL PROTOCOL-SEPTEMBER 1987-CFC PHASE OUT-OZONE

DEPLETION LEADING TO HEALTH HAZARDS

2. KIGALI AGREEMENT-25TH OCTOBER 2016-PHASE OUT HFC -HIGH GLOBAL

WARMING REFRIGERANTS

3. EPA SNAP RULE-OCTOBER 2016-PHASE OUT R134A,R404A, ETC.-HIGH

GLOBAL WARMING REFRIGERANTS

MONTREAL AGREEMENT

Due to serious ill effects resulting from depletion of

ozone, resulted in Montreal protocol-16Th

September 1987 where almost all countries (186)

agreed to phase out CFC’s in a time bound

program. This was the single first protocol when all

countries unanimously agreed to phase out CFC

refrigerants containing Chlorine molecule.

A historic global climate deal was reached in Kigali, on 25th

October 2016 Rwanda at the Twenty-Eighth Meeting of the Parties

to the Montreal Protocol on Substances that Deplete the Ozone

Layer (MOP28). The Kigali Amendment which amends the 1987

Montreal Protocol aims to phase out Hydrofluorocarbons (HFCs), a

family of potent greenhouse gases by the late 2040s. Under Kigali

Amendment, in all 197 countries, including India. The Kigali

Agreement or amended Montreal Protocol for HFCs reduction will

be binding on countries from 2019. It also has provisions for

penalties for non-compliance

KIGALI AGREEMENT-25th October 2016

EPA SNAP(Rule20) July 2015

(Significant New Alternatives Policy Program) spells

out phasing out of refrigerants R404A and R507

October2016-Most of the countries decided to

phase out R134a, R404a, R517, R410A and look for

natural refrigerants as a long term solution

Ref: Euromon document

Alternate Long Term Solutions

1. PHASE OUT AL MANMADE SYNTHETIC CHEMICALS

2. CONCENTRATE RESEARCH ON USE OF NATURAL REFRIGERANTS-AMMONIA,

CARBON DIOXIDE, HYDROCARBONS

3. RESEARCH ON ALTERNATE TECHNOLOGIES-SOLAR, WIND POWER, AIR

THERMOELECTRIC, MAGNETIC MATERIALS, PHASE CHANGE MATERIALS ETC.

4. HAVE NO REGRET SOLUTIONS AS A LONG TERM MEASURE

NATURE HAS SOLUTIONS FOR EVERY PROBLEM AND IS THE

ULTIMATE IN TECHNOLOGY

Refrigerant’s Time-line

1875 1900 1925 1950 1975 20001850

SO2

NH3

CFCs

CH3Cl

HCFCs

HFCs

HCs

air

water

CO2

© A Pearson 1999

CYCLE REPEATS9

History of Refrigerants

Why Low Charge Ammonia Systems?

1. Good and bad about Ammonia refrigerant

2. Why low charge Ammonia systems

3. Comparison between standard and low charge system

5. Low charge system components

6. Low charge system options

Ammonia Refrigerant Advantages

1. ODP-0

2. GWP < 1

3. ATMOSPHERIC LIFE- 0.01 YEARS

4. NATURAL REFRIGERANT

5. HIGHEST EFFICIENCY-BETTER HEAT TRANSFER PROPERTIES

6. EASIER OIL MANAGEMENT

7. LOW COST-EASY AVAILABILITY

8. AND MANY MORE

WHY AMMONIA?

Comparison of Various Refrigerants

ASHRAE Fundamentals 2013 Table 8-29.8

Refrigerant For positive Temperature cold rooms-+400C/20C

For secondary fluids operation+400C/-50C

For low temperature cold rooms-+400C/-250C

Ammonia-R717 6.20 4.965 2.91

R410A 5.43 4.80 2.50

R134a 5.88 4.67 2.70

R404A 5.18 4.07 2.26

R22 5.93 4.74 2.79

Ammonia C.O.P. (Efficiency)Comparison with other

refrigerants for various applications

Refrigerant For positive

Temperature cold rooms-

+400C/20C

For secondary

fluidsoperation

+400C/-50C

For low

temperature cold rooms-

+400C/-250C

Blast

freezers/IQF+400C/-400C

Ammonia-

R7176.20 4.965 2.91 2.06

R410A 5.43 4.80 2.50 1.75

R134a 5.88 4.67 2.70 1.88

R404A 5.18 4.07 2.26 1.52

R22 5.93 4.74 2.79 1.98

WHY AMMONIA?

LATENT HEAT COMPARISON @ 4-50CAMMONIA IS FAR BETTER IN COMPARISON AS IT IS THE LATENT HEAT WHICH MAKES REFRIGERATION WORK

1. Water R-718- 2489.04kJ/kg

2. Ammonia – R717- 1247.85kJ/kg

3. R410A- 214.48kJ/kg

4. HCFC 22/R22- 201.79kJ/kg

5. HFC 134a/R134a- 195.52kJ/kg

6. R404A- 162.03kJ/kg

WHY AMMONIA?

Ammonia Refrigerant Disadvantages

1. TOXICITY

2. FLAMMABILITY- (NO LONGER A CRITICAL CONSIDERATION)

3. HIGH DISCHARGE TEMPERATURES-MEANS TWO STAGE OPERATION FOR

SOME LOW TEMPERATURE APPLICATIONS

4. OIL NOT MISCIBLE AND REQUIRES DRAINING FROM MANY POINTS

ASHRAE Standard 34.1-2013-Flammability

Flammability in Air @ 60°C & 101.3 kPa ASHRAE Standard Safety Group

Higher Flammability

LFL or ETFL60 ≤ 100 g/m3 OR HOC ≥ 19 MJ/kg

A3 B3

Lower Flammability

LFL or ETFL60 > 100 g/m3 & HOC < 19 MJ/kg

A2 B2

Lower Flammability

LFL or ETFL60 > 100 g/m3 & HOC < 19 MJ/kg

with a maximum burning velocity of ≤ 10 cm/s

A2L B2L

No flame Propagation A1 B1

Flammability in Air @ 60°C & 101.3 kPaLower Toxicity

OEL ≥ 400PPM

Higher

Toxicity

OEL

< 400 PPM

LFL = Lower Flammability Limit

ETFL60 = Elevated Temperature Flame Limit @ 60°C

HOC = Heat Of Combustion, OEL-Occupational Exposure Limit

Toxicity

5 PPM Onwards Detectable(3-5mg/m3)

25 PPMDetected by most – no health hazard

exposure 10 – 15 years

100 PPM No dangerous effects, minor irritation.

400 – 700

PPM

Irritation Eyes, Nose, Mucous . Lead to

dryness

1700 PPM Cough, Cramp, Serious Irritation, Injuries

2000 PPM Can Lead to Death

7000 PPM Lethal within few minutes

HIGH DISCHARGE TEMPERATURE

Refrigerant Cp/Cv at

boiling point

or at

Atmospheric

pressure

Approximate isentropic

Discharge Temperature 0C

At +400C/-200C

R22 1.236 75

R134a 1.154 55

R404A 1.166 58

R410A 1.244 70

R717(Ammo

nia)

1.348 145

VARIOUS AMMONIA REFRIGERATION SYSTEMS

1. Gravity Flooded systems

2. Forced feed pump circulation systems

3. DX systems-(Still rare)

Static

height

Gravity Flooded System

Pumped System-Overfeed Systems

Gravity Flooded System Characteristics

1. Similar characteristics as pumped systems

2. No extra pump & pump energy necessary

3. Static pressure (liquid column) necessary to

compensate for pressure drop in the coil

Why Overfeed?

1. More than 3 to 4 freezers

2. Processing area away from machine room

3. Low temperature applications

4. Better efficiency

5. Better Dependability

6. Easy Fault Location

Flooded Air Coil

FLOODED COOLER IS MORE EFFICIENT THAN DX COOLER

Direct Expansion Air Coil

STANDARD COMPONENTS OF REGULAR SYSTEM

1. Compressor-Reciprocating or screw –open type

2. Condensers- Atmospheric, shell and tube, evaporative or PHE-

mostly water cooled

3. Expansion devices-Low side Float valve, Hand expansion valve

or motorized control valve in HP liquid line before evaporator

4. Evaporator-Application oriented, such as cold room air

coolers, S&T or. PHE chillers for water or brine, ice makers, plate

freezers, IQF or blast freezers etc.

Recent Advancement 31

Semi Hermetic Ammonia Scroll Compressor

7 kW ammonia reciprocating compressor

Semi-hermetic ammonia

compressor

Danfoss Sensors

GRAVITY FLODED ACCUMULATOR

ACCUMULATOR

BRINE CHILLING PLANT WITH S&T CONDESER/CHILLER

PUMP

CIRCULATION

SYSTEMS

Pump Circulation-Piping and control arrangement-LP VESSEL

Water cooled Atmospheric condenser

Shell and Tube Condenser

Evaporative Condensers

Air Cooled Ammonia Condenser

PHE Semi Welded Condenser

AMMONIA RECEIVERS

Flooded Ammonia Shell-and-Tube Liquid Cooler

SURGE DRUM ON CHILLER

ALFA LAVAL PHE WITH “U” Turn Accumulator

Comparison between Shell and Tube and PHE evaporators

IMPORTANT CONSIDERATIONS-COIL DESIGN-AIR CIRCULATION, FAN

SELECION

IQF

http://www.google.co.in/url?sa=i&rct=j&q=iqf&source=images&cd=&cad=rja&docid=ipdi5Lz3Ip53GM&tbnid=jN6qPK8g-FJwkM:&ved=0CAUQjRw&url=http://www.slattumprodukter.no/default.pl?showPage=167&ei=b5JjUcilLdOz0QXIuoCgCg&bvm=bv.44990110,d.ZGU&psig=AFQjCNGaFVogupsorAnYWYQkCqGCWTGa2Q&ust=1365566267360168

SPIRAL FREEZER

http://www.google.co.in/url?sa=i&rct=j&q=spiral+freezer&source=images&cd=&cad=rja&docid=_1q2uchx_8l_WM&tbnid=zYL6uYbZmiQqxM:&ved=0CAUQjRw&url=http://www.freezer-services.co.uk/freezer-services-news&ei=qJRjUY2TKeeK0AWFu4GQCw&bvm=bv.44990110,d.ZGU&psig=AFQjCNGcxehY57hVcqnDGDBrit1agiaimw&ust=1365566984965314

PLATE FREEZER

http://www.google.co.in/url?sa=i&rct=j&q=Plate+freezer&source=images&cd=&cad=rja&docid=e4DPr9LbYDcHwM&tbnid=mK9ixwOZatKSIM:&ved=0CAUQjRw&url=http://worldbase.xm15.host.35.com/products1.asp&ei=vZVjUcXGG-ec0AXMmoGQBg&bvm=bv.44990110,d.ZGU&psig=AFQjCNHGHb0eI2fEuwMfUNWvGD_xIP9ayw&ust=1365567190025210

FALLING FILM COOLER

http://www.google.co.in/url?sa=i&rct=j&q=falling+film+cooler&source=images&cd=&cad=rja&docid=bYM29DbiOrxWKM&tbnid=YrfbXkpcsR9DqM:&ved=0CAUQjRw&url=http://www.anthermo.de/en/heat-exchangers/falling-film-chiller-sherd-ice-generator&ei=2pZjUcy0AsKc0wXltICwCw&bvm=bv.44990110,d.ZGU&psig=AFQjCNFZfqeG23IDcGbya2XkfO1n8V-Vdw&ust=1365567568475841

FLAKE ICE MACHINE

http://www.google.co.in/url?sa=i&rct=j&q=flake+ice+maker&source=images&cd=&cad=rja&docid=kMgq54OXUftpQM&tbnid=COYQLBVi7HXg3M:&ved=0CAUQjRw&url=http://www.bmil.com/howe/&ei=wLZjUar1KKTC0QX5vYHIAQ&bvm=bv.44990110,d.ZG4&psig=AFQjCNH46Xz0JmtSlVL-gWBXwAxvlRbJdg&ust=1365575381705275

Hand operated Liquid Flow Regulating Valve

Hand Operated Expansion valve

FRV-Automatic Liquid Flow Regulating Valve

HIGH PRESSURE FLOAT – WITT OR DANFOSS

DCE REFRIGERATION PVT LTD.

What is Low Charge Ammonia Systems

Low charge systems are defined as systems having no more than

1.3kg/kW

Low charge factory made packaged refrigeration systems of less

than 0.3kg/ton are available using shell and plate heat exchangers.

Use of High side float eliminates use of H.P. receiver.

Systems with as low as 0.06kg/kW charge are also available for

some applications

Ref: ISHRAE JOURNAL JAN-March 2017-Star Refrigeration UK-R. Lamb

CONVENTIONAL AMMONIA REFRIGERATION SYSTEM

USING PHE CONDENSER/CHILLER- P&I DRAWING


Sr No. Equipment Volume Volume Vapour Liquid Vapour

NH3

Liquid

NH3

Total NH3

Liters m3 % % Kg Kg Kg

1 Compressor 500.00 0.50000 100.00% 0.00% 1.730 0.000 1.730

2 Suction line 94.26 0.09426 100.00% 0.00% 0.326 0.000 0.326

3 Discharge line 60.33 0.06033 100.00% 0.00% 0.723 0.000 0.723

4 Liquid Line 61.94 0.06194 0.00% 100.00% 0.000 35.891 35.891

5 Accumulator 1486.00 1.48600 70.00% 30.00% 3.599 284.692 288.292

6 Ammonia Receiver967.00

0.96700 70.00% 30.00% 8.111 168.106 176.217

7 PHE Condenser 2.4 lit X 56 Cassetees 146.40 0.14640 80.00% 20.00% 1.403 16.967 18.371

8 PHE Chiller 1.4 lit X 69 Cassetees 96.60 0.09660 0.00% 100.00% 0.000 61.690 61.690

TOTAL AMMONIA CHARGE 15.89 567.35 583.24

CONVENTIONAL AMMONIA REFRIGERATION SYSTEM

- AMMONIA CHARGE CALCULATIONS FOR 350 TR CAPACITY


LOW CHARGE AMMONIA REFRIGERATION SYSTEM

WITH HIGH SIDE FLOAT & NO RECEIVER- P&I DRAWING

H.SIDE

FLOAT

No HP RECEIVER

Sr No. Equipment Volume Volume Vapour Liquid Vapour

NH3

Liquid

NH3

Total NH3

Liters m3 % % Kg Kg Kg

1 Compressor 500.00 0.50000 100.00% 0.00% 1.730 0.000 1.730

2 Suction line 94.26 0.09426 100.00% 0.00% 0.326 0.000 0.326

3 Discharge line 60.33 0.06033 100.00% 0.00% 0.723 0.000 0.723

4 Liquid Line 29.87 0.02987 0.00% 100.00% 0.000 17.308 17.308

5 High Pressure Float 19.00 0.01900 40.00% 60.00% 0.026 7.280 7.306

6 Accumulator 1486.00 1.48600 90.00% 10.00% 4.628 94.897 99.525

7 PHE Condenser 2.4 lit X 56 Cassetees 134.40 0.13440 80.00% 20.00% 1.288 15.576 16.865

8 PHE Chiller 1.4 lit X 69 Cassetees 96.60 0.09660 30.00% 70.00% 0.000 43.183 43.183

TOTAL AMMONIA CHARGE 8.72 178.25 186.97


LOW CHARGE AMMONIA REFRIGERATION SYSTEM

- AMMONIA CHARGE CALCULATIONS FOR 350 TR CAPACITY

COMPARISION

PARTICULARLOW CHARGE AMMONIA REFRIGERATION

SYSTEM (RECEIVERLESS)

CONVENTIONAL AMMONIA REFRIGERATION

SYSTEM (WITH RECEIVER)

COMPONENTSCOMPRESSOR + CONDENSER +

EVAPORATOR

COMPRESSOR + CONDENSER

+EVAPORATOR +RECEIVER

EXPANSION DEVICE HP FLOAT HAND EXPANSION VALVE

LEVEL CONTROL DEVICE NOT REQUIREDELECTRONIC FLOAT / LEVEL CONTROLER &

SOLENOID VALVE

REGRIGERANT CHARGE 186 Kg 583 Kg

ADDITIONAL CONTROL HIGH LEVEL TRIP MAY BE PROVIDED

PLANT CAPACITY 350 TR 350 TR


REFRIGERATION SYSTEM WITH RECEIVER


REFRIGERATION SYSTEM WITHOUT RECEIVER


FRIGERATION SYSTEM


REFRIGERATION SYSTEM


LVS SYSTEM BY JBT -FRIGOSCANDIA


LATEST TRENDS

1. Sealed or semi-hermetic compressors for Ammonia

2. Shell and plate condenser and chillers

3. Air cooled package chillers

4. Direct Expansion systems using miscible oils

5. Aluminium air coolers

6. Roof mount packages for commercial air conditioning

AIR COOLED AMMONIA PACKAGE CHILLER-Azane by Star

Refrigeration UK-784kW-200kg (0.86kg/Ton)refrigerant

charge

WATER COOLED PACKAGE CHILLER-SCREW COMPRESSORS

& PHE CONDENSER/COOLER-856 kW-86 kg0.353kg/TR

Jhonson controls uses ammnia system to air

condition 5000 sq.m of of office area using Four

ammonia water chilling units each of 2MW capacity

One of The Four package Ammonia Chillers being installed

at Heathrow Airport

AIR COOLED AMMONIA PACKAGE

Aluminum Coolers

Electronic Expansion Valve for Ammonia –Danfoss

TYPE-AKVA

AKVA

Direct Expansion Evaporator-(DX)

WATER CHILLER USING RECIPROCATING COMPRESSOR

& ENCLOSED SHELL-PHE CONDENSER/COOLER

ROOF TOP AMMONIA WATER CHILLER

Modern Packaged Ammonia Systems

•New design (PHEs or spray type shell & tube evaporator)

•Liquid injection system

•Better efficiency (>30%) than HFC134a

•Less charge (0.02 to 0.5 kg/kW) for dry and flooded evaporation

•Higher discharge pressure (up to 40 bar)

•Safety level increased significantly towards “zero leak”

•Used in Europe for both display cabinets and space conditioning

Ammonia for A/C and Commercial Refrigeration

•Ammonia A/C with central plants

•Ammonia display freezer cabinets

•Independent circuits

•Secondary refrigerants used

•Risk free AC&R

AMMONIA CHILLER WITH PHE CONDENSER/COOLER

STUTTGART AIRPORT WITH AMMONIA CHILLERS

ONE OF FOUR PACKAGE AT HEATHROW AIRPORT

The Ozeaneum In Stralsund

Gernmany:Underwater world

CO2 Ammonia Cascade

Conclusions and vision for future

1. Use of low charge refrigeration systems

2. Use of Natural Refrigerants, hydrocarbons, CO2 as refrigerants

3. Use of Phase change material-Eutectic plates

4. Shell and plate condenser and chillers

5. Air cooled package chillers

6. Direct Expansion systems using miscible oils

7. Oil free compressors

8. Aluminium air coolers

9. Roof mount packages for commercial air conditioning

10.Use of alternate sources for energy like solar ,wind, thermoelectric,

magnetic refrigeration

11.Intelligent controllers for the entire system

12.Increased use of VFD for speed control of compressor-motors,

condenser/evaporator fans and pumps


BY

RAMESH PARANJPEY

ASHRAE FELLOW LIFE MEMBER

CHAIRMAN ISHRAE REFRIGERATION TECHNICAL GROUP

CELL PHONE : 98223 98220

MAIL ID: [email protected]

Website : http://Ramesh-paranjpey.com

mailto:[email protected]

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