Need Help in Refrigeration Calculation

[Jason_09]

Hi all experts,

I am doing some research on District Cooling System, I have difficulties on some calculation matters below:

1. Is 1kWr=0.284 RT correct?
2. Is 1 MJ= 0.079 RT hour correct?
3. Is 1 kWr = 1 kW electrical? I suppose is the same
4. say an office tower consumes 10,000RT, does it mean it consumes approx. 35MW of electricity?if this understanding is correct, it operates for 10hours it uses 350MWh?
5. The above calculation seems to miss out the efficiency of equipment to calculate the electricity consumes for RT, is there anything missing...?

Many thanks,
Jason

[icecube51]

Hi all experts,

I am doing some research on District Cooling System, I have difficulties on some calculation matters below:

1. Is 1kWr=0.284 RT correct?
2. Is 1 MJ= 0.079 RT hour correct?
3. Is 1 kWr = 1 kW electrical? I suppose is the same
4. say an office tower consumes 10,000RT, does it mean it consumes approx. 35MW of electricity?if this understanding is correct, it operates for 10hours it uses 350MWh?
5. The above calculation seems to miss out the efficiency of equipment to calculate the electricity consumes for RT, is there anything missing...?

Many thanks,
Jason

on what ratio is the calculation based ? a cooling load of 24Hrs ??? a COP of ....??
what are you using for cooling, refrig?? water?? brine??
are the 10000RT day-ore night consumptions??? ore both??

i think you have to be a bit more specific M8 if you want help on yore project.

Ice

[Tesla]

Hi Jason09
District coolin? 1, yes. 2, yes. 3, no. 4, no. 5, yes. You need system COP to calculate kWrefrigeratoin to kW electical. Or you could just measure it, and analyse power bill.

[Peter_1]

Hi all experts,

I am doing some research on District Cooling System, I have difficulties on some calculation matters below:

1. Is 1kWr=0.284 RT correct?
2. Is 1 MJ= 0.079 RT hour correct?
3. Is 1 kWr = 1 kW electrical? I suppose is the same
4. say an office tower consumes 10,000RT, does it mean it consumes approx. 35MW of electricity?if this understanding is correct, it operates for 10hours it uses 350MWh?
5. The above calculation seems to miss out the efficiency of equipment to calculate the electricity consumes for RT, is there anything missing...?

Many thanks,
Jason

IN the 1st place, what is kWr and RT?

[Yuri B.]

Probably, kW refrigerating and http://en.wikipedia.org/wiki/RT_(energy)

[icecube51]

hey peter, i was thinking kwr - kilowatt /Hrs , and RT- refrig ton.

just guessing, Ice

[ibraheem]

Refrigeration Tonnage =TR or RT, and KW/Hr=kilowat per hours,
it is seems to me you are confusing , you need to know what you doing not merely conversion of unit, many people do the same mistake because they are not from this discipline, alway know that mechanical units are different to electricals as well energy, and you must know that energies and convertable but application of covertibilities must be known to the person want to convert it ,for example, in Hvacr we may have the energy (cooling load) given in Btu/hr you may convert it to kilowatt/hr, and we can convert these energies to electrical kilowat and mechanical horse power, try to know more about this, and you can download the engineering convert tools online

[sterl]

In SI: Joule is the unit of energy; Watt is unit of power. A KWhr represents power applied or consumed over an hour period. For motors: Volts X Amps X efficiency X PF= KW. Use the motor for an hour and the formula will yield consumption of power in KWhr.

KWr is Kilowatts of refrigerating effect, and is the equivalent of 0.284 TR. But a compression refrigeration system moves heat, it doesn't convert electricity to heat as does a strip heater.

Thus the definition of COP: (KW of refrigerating effect / KW of electrical input).... For an air conditioning system the ratio is about 4 to 5.

So for your 10000 TR A/C load, the metric capacity equivalent is 35160 KW and steady state, you would need somethin around 7500 KW of electrical input. If that operated for one hour, it would consume 7500 KWhr of electricity...