Condensing unit ККА-24-W. Technical design

The theses from explanatory note and the examples of design documents, developed within the framework of technical design of water-cooled condensing unit ККА-24-W, are given below.

Unit reference designation – KKA-Q-W,

where

KKA – condensing unit;

Q – refrigeration capacity, kW;

W – cooling of condenser heat-exchange surface with water.

At the technical design stage the estimation of required technical characteristics and parameters, essential for specifying the equipment grades and dimension types selected within the framework of sketch design, was performed. The sketch design provides the required technical characteristics in all operation modes of the unit and, consequently, of the entire refrigeration unit equipment system, and also the selection of additional accessories necessary for providing the reliable operation of the refrigeration unit.

At the technical design stage it was decided to include the refrigeration unit control board, comprising the start-control devices for unit and air coolers control, as a component of the condensing unit. The air coolers are installed in cooling chambers serviced with this unit. The following devices were also included into the condensing unit:

protective automation devices:

  • dual pressure switch KP 15 (also the names “pressure regulator” or “ pressostat” are used in technical literature). It is used for protection from condensation pressure inadmissible increase and evaporation pressure decrease;
  • differential oil pressure switch MP 55;

and devices for diagnostics:

  • pressure gauge for refrigerant condensation pressure measurement;
  • vacuum pressure gauge for refrigerant evaporation pressure measurement.

Protective automation and diagnostics devices are now installed on the panel intended for them.

Also at the technical design stage the elements for refrigerant pipeline fixation were used to prevent the displacement, mechanical damages and vibration compensation in a discharge line.

Sight glass SGI 16s with moisture indicator was also included into the unit to perform the diagnostics of refrigerant dryness factor at filter-drier outlet.

Агрегат компрессорно-конденсаторный ККА-24-В

Figure Т.1 – Unit general view approved at the technical design stage

Table Т.1 – Unit technical characteristics in nominal mode

Parameter name

Measurement units

Value

1

Refrigeration capacity

kW

23,6

2

Refrigeration capacity*

23,6

3

Condenser capacity

34,6

4

Compressor type

-

Semi-hermetic

reciprocating one

5

Compressor model

4NES-20Y

6

Refrigerant in use

R507A

7

Refrigerant evaporation temperature

°С

-15

8

Refrigerant condensation temperature

45

9

Refrigerant suction vapours temperature

20

10

Water temperature at condenser inlet

32

11

Discharge temperature without cooling

94,5

12

Liquid overcooling

K

0

13

Cooling water flow rate through condenser

m3/h

5

14

Refrigerant mass flow rate

kg/h

726

15

Power supply

-

400 V – 3 phases – 50 Hz

16

Allowable range of power supply voltage

V

380-420

17

Consumable current

A

19,8

18

Consumable power

kW

11

19

Capacity regulation degree

%

100

20

СОР/EF (efficiency factor)

-

2,14

21

СОР/EF*

2,14

22

Refrigerant amount in receiver**

kg

14,4

23

Product dry weight

375

* As per standard EN12900 (suction vapours temperature is 20°С, liquid overcooling is 0 К)

** At liquid refrigerant temperature +20°С and receiver filling volume 90%

 Table Т.2 – List of unit main elements

Element name

Designation

Manufacturer

Compressor 4NES-20Y-40P

Bitzer

Condenser K283H
Receiver F152H
Oil separator OSH-409

Alco

Filter-drier DML305s

Danfoss

Ball valve GBC 16s
Check valve NRV 19s
Dual pressure switch KP 15
Differential pressure switch MP 55

condensing-unit-KKA-24-W-GCh-ENG

Figure Т.2 – Condensing unit ККА-24-V. Overall, connecting dimensions and arrangement.

The unit overall and connecting dimensions, main elements and assembly units layout, are shown in the Figure.

To become familiar with all design stages and examples of their performance, proceed to the review of the article “Stages of designing”.

Поделитесь с друзьями
  • Facebook
  • Twitter
  • LinkedIn
  • Добавить ВКонтакте заметку об этой странице

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>