How does a chiller work??

Question

I was in a building and saw a 750 ton chiller (basement) for a 40 story building with a rooftop water tower.

I know that the chiller has condenser and eveporator. But how does work for cooling and heating??

I have no knowledge in chillers whatsoever, if anyone can explain it me clearly that would be great.

Thanks!!!

Answer 1

Chillers are used for cooling, not heating.

The large horizontal tank you see contains a bundle of copper tubes thru which water is circulated. The bundle is immersed in a pool of refrigerant.  A large vapor pump situated above the refrigerant pool produces a partial vacuum causing the refrigerant to boil at a low temperature, cooling the circulating water in the tubes.   The cold water is pumped to the AC system where it cools the building air.  The warmed water returns to the refrigerant pool to be cooled again.

The vapor pump compresses the refrigerant vapor, raising its temperature by compression, and sends the hot vapor to the condenser where it encounters another tube bundle,  This bundle has water circulating from the cooling tower which appears cold to the hot vapor and the vapor condenses back to liquid and is returned to the refrigerant pool.

The refrigerant circulates in a closed loop as does the cooling water going to the AC system/..  The water in the cooling tower is cooled by evaporation and is where the building's heat is finally rejected.  The cooling tower requires constant make-up water to compensate for evaporation losses.

One ton of refrigeration is the amount of cooling necessary to produce one ton of ice and is the way cooling capacity is measured.

Answer 2

*First of all understand the meaning of chiller.

*A vapor-compression chiller uses a refrigerant internally as its working fluid. Many refrigerants options are available; when selecting a chiller, the application cooling temperature requirements and refrigerant's cooling characteristics need to be matched. Important parameters to consider are the operating temperatures and pressures.

There are several environmental factors that concern refrigerants, and also affect the future availability for chiller applications. This is a key consideration in intermittent applications where a large chiller may last for 25 years or more. Ozone depletion potential (ODP) and global warming potential (GWP) of the refrigerant need to be considered. ODP and GWP data for some of the more common vapor-compression refrigerants; R-134a ODP = 0 and GWP = 1300; R-123 ODP = 0.012 and GWP = 120; R-22 ODP = 0.05, GWP = 1700.

*Industrial chillers typically come as complete packaged closed-loop systems, including the chiller unit, condenser, and pump station with recirculating pump, expansion valve, no-flow shutdown, internal cold water tank, and temperature control. The internal tank helps maintain cold water temperature and prevents temperature spikes from occurring. Closed loop industrial chillers recirculate a clean coolant or clean water with condition addititives at a constant temperature and pressure to increase the stability and reproducibility of water-cooled machines and instruments. The water flows from the chiller to the application's point of use and back.

http://en.wikipedia.org/wiki/Chiller

*For evaporator,visit:

http://en.wikipedia.org/wiki/Evaporator

*Better you go through vapour compression refrigeration cycle:

http://en.wikipedia.org/wiki/Vapor-compr...

*For rooftop water tower,pl. visit:

http://en.wikipedia.org/wiki/Water_tower