°C and leaving at 6°C. Calculate the refrigeration effect in kW and the COP of the chiller.

To calculate the refrigeration effect in kW, we need to know the specific heat capacity of water. The specific heat capacity of water is approximately 4.186 kJ/kg°C.

First, we need to calculate the mass flow rate of water being cooled:

Mass flow rate = Density of water * Volume flow rate
Mass flow rate = 1000 kg/m3 * 20 m3/hr
Mass flow rate = 20,000 kg/hr

Next, we can calculate the temperature difference:

Temperature difference = Final temperature - Initial temperature
Temperature difference = 6°C - 12°C
Temperature difference = -6°C

Since the temperature difference is negative, we need to take the absolute value:

Temperature difference = 6°C

Now we can calculate the refrigeration effect:

Refrigeration effect = Mass flow rate * Specific heat capacity of water * Temperature difference
Refrigeration effect = 20,000 kg/hr * 4.186 kJ/kg°C * 6°C
Refrigeration effect = 502,320 kJ/hr

To convert kJ/hr to kW, we divide by 3600 (since there are 3600 seconds in an hour):

Refrigeration effect = 502,320 kJ/hr / 3600
Refrigeration effect = 139.53 kW

The COP (Coefficient of Performance) of a chiller can be calculated using the formula:

COP = Refrigeration effect / Power input

Since the capacity of the chiller is given as 30 tons of refrigeration, we can convert it to kW:

30 tons of refrigeration = 30 * 12,000 BTU/hr
30 tons of refrigeration = 360,000 BTU/hr
1 BTU/hr = 0.29307107 W
360,000 BTU/hr = 360,000 * 0.29307107 W
360,000 BTU/hr = 105,385 W
105,385 W = 105.385 kW

Now we can calculate the COP:

COP = Refrigeration effect / Power input
COP = 139.53 kW / 105.385 kW
COP = 1.32

Therefore, the refrigeration effect of the chiller is 139.53 kW and the COP is 1.32.