Lezione tenuta da Ing. Piero Trevisan (BITZER, docente CSG) alla Mostra Convegno Expocomfort 2014 presso la Fiera di Milano il 19/03/2014

1. BITZER Semi-hermetic Reciprocating
Compressors for R290 and R1270
Applications
MOSTRA CONVEGNO
Milan, 18th to 21st March 2014

2. Contents

3. BITZER // MS (AS) // BITZER Semi-hermetic Reciprocating Compressors for R290 and R1270 Applications // Page 3
Contents
/ Introduction
/ Refrigerant properties of R290 and R1270
/ Product range and designation
/ Compressor technology
/ Software selection
/ Application limits
/ System requirements

4. Introduction

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Introduction
/ With the recently increasing demand for using refrigerants with low
Global Warming Potential (GWP), systems with hydrocarbons get an
important role in the refrigerant market again
/ Compared to most HFC systems, hydrocarbon systems require special
safety measures for the design, assembly, operation and maintenance,
what limits their general application

6. Refrigerant Properties
of R290 and R1270

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Refrigerant Properties of R290 and R1270
/ Naturally occurring halogen-free hydrocarbons
 No Ozone Depletion Potential (ODP = 0)
 Negligible Global Warming Potential (GWP = 3)
/ Favorable thermodynamic properties
/ Low toxicity level (1000 ppm) comparable with HCFC and HFC
refrigerants
/ Flammable
 R290: LFL = 1,7 Vol.% in air / UFL = 10,9 Vol.% in air
 R1270: LFL = 2,0 Vol.% in air / UFL = 11,1 Vol.% in air
/ Good compatibility with common metals and elastomers, what allows the
use of hermetic and semi-hermetic compressors
 Zinc and alloys with Magnesium levels above 2% shall be avoided

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Refrigerant Properties of R290 and R1270
/ Extremely high solubility in all common lubricants, what leads to a
considerable decrease of the oil viscosity in the compressor especially
at low oil temperature and high suction pressure
 Sufficient suction gas superheat shall be ensured (Δtoh = 20 K)
/ Good solvents for sediment, grease and oil in the pipe work
 Maximum cleanness in the system, brazing with a protective gas
and suction side filter are required
/ High degree of purity, i.e. “2.5”
 Even if hydrocarbons do not contain elements with tendency to
form acids, a high moisture content in the system must be
avoided

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Refrigerant Properties of R290 and R1270
/ Refrigerant properties compared to R22 and some HFC refrigerants

10. BITZER // MS (AS) // BITZER Semi-hermetic Reciprocating Compressors for R290 and R1270 Applications // Page 10
Refrigerant Properties of R290 and R1270
/ Pressure levels compared to R22 and some HFC refrigerants

11. BITZER // MS (AS) // BITZER Semi-hermetic Reciprocating Compressors for R290 and R1270 Applications // Page 11
Refrigerant Properties of R290 and R1270
/ Volumetric cooling capacity compared to R22 and some HFC refrigerants

12. BITZER // MS (AS) // BITZER Semi-hermetic Reciprocating Compressors for R290 and R1270 Applications // Page 12
Refrigerant Properties of R290 and R1270
/ Comparison of performance data of semi-hermetic reciprocating
compressor compared to R22

13. Product Range and Designation

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Product Range and Designation
/ The capacity range

15. BITZER // MS (AS) // BITZER Semi-hermetic Reciprocating Compressors for R290 and R1270 Applications // Page 15
Product Range and Designation
/ Explanation of model designation
4 N E S P – 20 P – 40P Index for number of cylinders
4 N E S P – 20 P – 40P Identification letter for bore x stroke
4 N E S P – 20 P – 40P Identification letter for ECOLINE series
4 N E S P – 20 P – 40P Code for centrifugal lubrication
4 N E S P – 20 P – 40P Identification letter for HC special design
4 N E S P – 20 P – 40P Code for motor size
4 N E S P – 20 P – 40P Identification letter for oil charge for HC
4 N E S P – 20 P – 40P Motor code

16. Compressor Technology

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Compressor Technology
/ Risk assessment according to EU directives 94/9/EC (ATEX 95),
1999/92/EC (ATEX 137) and to regulations on product safety, safety at
workplace, prevention of accidents on BITZER semi-hermetic
reciprocating compressors for the operation in the Zone 2
/ Specially designed for the use with hydrocarbons and differ in the
technical design, i.e. electrical equipment, safety mechanism and oil
filling, from the standard compressors for HFC and HCFC refrigerants

18. Software Selection

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Software Selection
/ R290 compressor selection (OEM mode at myBITZER)

20. BITZER // MS (AS) // BITZER Semi-hermetic Reciprocating Compressors for R290 and R1270 Applications // Page 20
Software Selection
/ R1270 compressor selection (OEM mode at myBITZER)

21. Application Limits

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Application Limits
/ Semi-hermetic reciprocating compressors on R290
 Low-temperature and medium temperature cooling applications
 Air-conditioning applications
to Evaporating temp.
tc Condensing temp.
toh Suction gas temp.
Δtoh Suction gas superheat

23. BITZER // MS (AS) // BITZER Semi-hermetic Reciprocating Compressors for R290 and R1270 Applications // Page 23
Application Limits
/ Semi-hermetic reciprocating compressors on R1270
 Low-temperature and medium-temperature cooling applications
to Evaporating temp.
tc Condensing temp.
toh Suction gas temp.
Δtoh Suction gas superheat

24. System Requirements

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System Requirements
/ A risk assessment of the entire system must be carried out by the
operator under consideration of the ATEX Zone 2 (an explosive mixture
is not likely to occur in normal operation and if it occurs it will exist only
for a short time)
/ Local safety regulation at workplace and further local regulations must
be applied in the system design, place on the market and operation of
the system
/ Maximum refrigerant charge for A3 refrigerants depending on the
installation area and system installation site according to EN 378-1
must be considered
/ The system must be approved by a notified body

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System Requirements
/ Compressor motor protection device is delivered
separated for installation in the switchboard
/ Electrical equipment in enclosure class IP 54
can be installed inside the Zone 2. If higher
system requirements are demanded, electrical
components with reed switch connected to an
isolation barrier should be used
/ The system must have the label “Attention Fire
Hazard” (B.3.2 / ISO 3864)

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System Requirements
/ For indoor installation, extraction air fan and gas sensors are commonly
used as safety measures against a dangerous concentration of the
flammable refrigerant in the air
/ The right position of the gas sensors of the system must be tested and
the system must be switch off, if a dangerous concentration of
flammable refrigerant in the air is achieved
/ Design, assembly, operation and maintenance of refrigeration system
with flammable refrigerants of the A3 safety group require the
application of the safety rules and guidelines by the technical personnel
and should only be performed by authorized personnel, who have been
trained and instructed in all the works

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System Requirements
/ Further information about
applications on hydrocarbons with
BITZER semi-hermetic
reciprocating compressors on the
KT-660-3 (available soon)