Specifications

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19XR Refrigeration cycle (centrifugal chiller)
■ The compressor continuously draws refrigerant vapour from
the cooler, at a rate set by the amount of guide vane opening.
As the compressor suction reduces the pressure in the cooler,
the remaining refrigerant boils at a fairly low temperature
(typically 3 to 6°C). The energy required for boiling is
obtained from the water flowing through the cooler tubes.
With heat energy removed, the water becomes cold enough
for use in an air-conditioning circuit or process liquid
cooling.
■ After taking heat from the water, the refrigerant vapour is
compressed. Compression adds still more heat energy and the
refrigerant is quite warm (typically 37 to 40°C) when it is
discharged from compressor into condenser.
■ Relatively cool (typically 18 to 32°C) water flowing into the
condenser tubes removes heat from the refrigerant and the
vapour condenses to liquid.
■ The liquid refrigerant passes through orifices into the FLASC
(Flash Subcooler) chamber. Since the FLASC chamber is at a
lower pressure, part of the liquid refrigerant flashes to
vapour, thereby cooling the remaining liquid. The FLASC
vapour is recondensed on the tubes which are cooled by
entering condenser water. The liquid drains into a float valve
chamber between the FLASC chamber and cooler. Here a
float valve forms a liquid seal to keep FLASC chamber
vapour from entering the cooler. When liquid refrigerant
passes through the valve, some of it flashes to vapour in the
reduced pressure on the cooler side. In flashing, it removes
heat from the remaining liquid. The refrigerant is now at a
temperature and pressure at which the cycle began.
19XR REFRIGERANT CYCLE
1. FLASC chamber
2. Condenser water
3. Condenser
4. Condenser isolation valve
5. Transmission
6. Diffuser
7. Guide vane motor
8. Motor
9. Guide vanes
10. Impeller
11. Compressor
12. Back pressure orifice
13. Oil cooling
14. Oil filter
15. Oil pump
16. Stator
17. Rotor
18. Refrigerant cooling isolation valve
19. Float valve chamber
20. Filter drier
21. Orificed fitting
22. Moisture/flow indicator
23. Orificed fitting
24. Thermostatic expansion valves (TXV)
25. Distribution pipe
26. Cooler isolation valve
27. Evaporator
28. Chilled water
29. Refrigerant liquid
30. Refrigerant vapour
31. Refrigerant liquid/vapour
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