Calculating the needed water temperature for a coil

[aztec]

Hey everybody!

Let me get straight to the point:
I have a coil that uses chilled water too cool down air to a given temperature. The average apparature dew point is 13 degrees celsius.
Now based on the specs of coil and air, my job is to calculate the incoming and outgoing temperature of the chilled water (flow etc. is known).

Can you provide me with formulas or programs, or maybe just some advices which direction to go?

Thanks a lot in advance!

aztec

PS: Nice forums you have here...

[nike123]

What is dry bulb temperature or humidity
What is water flow? What is desired cooling capacity? What is air flow?

[aztec]

Coil Model:
Typical (1/2" Tube)
914 x 2300 4r 14f 8c

Air:
Barometer: 101.325 kPa
Altitude: 0m
Airflow: 7m³
On Coil: 30.0/19.0 ºC
OffCoil: 21.8/16.2 ºC
Cond Rate: 0 g/s
Pressure Drop: 0.198 kPa

Water:
Flow: 0.867 l/s
Velocity: 0.880 m/s
Pressure Drop: 31.5 kPa
Pipe Conn: 35mm

Performance (Dry Surface):
Duty: 67.7 kW


That's all the info I've got. Now based on that, I need the water inlet and leaving temperature.

Thanks a bunch!

[nike123]

Water:
Flow: 0.867 l/s
Velocity: 0.880 m/s
Pressure Drop: 31.5 kPa
Pipe Conn: 35mm

Performance (Dry Surface):
Duty: 67.7 kW

Your water side flow is not good:
ΔT=Q/(m*c)

http://www.refrigeration-engineer.co...ad.php?t=18816

Your ΔT is calculated as 18,65K and is way off of normal values (3-8K).

Your water flow should be around 3l/s.

Than you could calculate with around water in 15°C and water out 20°C