8/12/2019 ABB Technical Note - Cooling Systems_lowresf

http://slidepdf.com/reader/full/abb-technical-note-cooling-systemslowresf 1/2

 ABB is a leading supplier of synchronous

turbine-driven generators to power utili-

ties, paper mills, sugar plants, oil and gas

installations, and many other sectors.

We have been manufacturing generators

for more than 120 years and have exten-

sive application experience with tens of

thousands of installations all over the

world. ABB offers reliable and efficientpower generation with worldwide

support.

 Technical note

Synchronous generators for steam and gas turbinesPre-engineered generators - Cooling systems

One of the factors that determine the li fetime of a gen-

erator is temperature. As all losses generate heat it is

important to have a cooling system that can maintain a

sufficiently low operating temperature within all parts ofthe generator. In order to achieve this, pre-engineered

generators use a symmetrical cooling principle that

allows uniform cooling within the generator.

 Avai lable cool ing systems

 The pre-engineered generator line can be provided with three

different cooling methods depending on the ambient condi-

tions.

 − Open ventilated where the ambient air is used directly for

cooling. −  Air-to-water cooler where the internal air in the generator

is cooled by a top mounted water cooler.

 −  Air-to-air cooler where the internal air is cooled by the

ambient air through a top mounted tube heat exchanger.

Open ventilated (IC3A1 )

Pre-engineered generators are equipped as standard with an

open ventilated (IC3A1) cooling system with ducts on the air

inlets and outlet. The ducts are fitted with flanges for the con-nection of external air channels. The inlet air channels must

be equipped with filters (minimum filter class F6). This cooling

method is more dependent on ambient conditions than the

others, as dirt can be sucked into the generator and cause

contamination.

 The open venti lated cooling method also requires greater at-

tention to the design of the external air channels, for example:

 − Cold environment - avoiding stand-still draft into the gene-

rator.

 −

Pressure drop - maximum allowed pressure drop is 400Pafor the external ducts

 − Noise level - without external ducts the noise is typically

15dB higher than for an enclosed water cooled generator.

 − Mix of cold and warm air - as a minimum requires external

intake duct.

8/12/2019 ABB Technical Note - Cooling Systems_lowresf

http://slidepdf.com/reader/full/abb-technical-note-cooling-systemslowresf 2/2

 The following mater ials are used in a ir-to-water coolers:

 − Inner tube material: copper-nickel (90/10)

 − Outer tube material for double tube cooler: copper

 −

Plate fin material: aluminum − Cooler top housing material: Painted carbon steel

 −  Tube sheet materia l: naval brass (CuZn38Sn1)

 − Header material: rilsan coated steel (polyamide 11)

 − Cooler element casing material: galvanized steel

 Air-to-air cooler (IC6A1A6)

 This cooling method is suitable for generators installed in loca-

tions with limited or no access to cooling water. The standard

air-to-air cooler is tted with two external fans, each delivering

50% of the required cooling capacity.

 The following materials are used as standard in the air-to-air

cooler:

 −  Tube material: galvanized stee l or aluminum

 −  Tube plate material : mild steel

 − Intermediate plate material: mild steel

 The following materials are available as an option:

 −  Tube material: AISI 304L

 −

 Tube sheet materia l: AISI 304L − Intermediate plate material: AISI 304L

 − Pressure switches in cooler inlet air circuit

 The following fan congurations are available as options:

 −  Three external fans for a redundancy of 3 x 50%

 − Certified for hazardous area

Please note that the delivery time of the complete generator may

be affected by the choice of options.

   ©    C

  o  p  y  r   i  g   h   t   A   B   B .

   3   A   A   M   1   0   0   4   5   5

   E   N

   0   3  -   2   0   1   3

For more information please visit:

www.abb.com/motors&generators

We reserve the right to make technical changes or modify the contents of this

document without prior notice. With regard to p urchase orders, the agreed

particulars shall prevail. ABB Ltd does not accept any responsibility whatso-

ever for potential errors or possible lack of information in this d ocument.

We reserve all rights in this document and in the subject matter and illustra-

tions contained herein. Any reproduction, disclosure to third parties or utiliza-

tion of its contents - in whole or in part- is forbidden without prior written

consent of ABB Ltd.

 

© Copyright 2013 ABB. All Rights Reserved

 Air-to-water cooler (IC8A1W7 )

Pre-engineered generators can also be provided with an air-

to-water cooler. This cooling method is preferable if there is

access to cooling water. The air-to-water cooler is designed

for easy withdrawal of the cooler battery from the cooler top.

It is cleanable and provided with drain holes. The air-to-water

cooler is prepared for industrial charged, fresh or brackish

water and calculated and designed for a maximum fouling

factor of 0.00009.

 The air-to-water cooler is available with a water design pressure

of 0.6 or 1.0 MPa and a water test pressure of 0.9 or 1.5 MPa.

 The cooler can be provided with single or double tubes and

anges according to DIN (DN100) or ANSI (4”). Redundancy is

only available for coolers with the higher design and test pres-

sure (1.0/1.5 MPa).