00:01
We'd like to determine the mass flow rate of the refrigerant.
00:04
So from our chart of r134a, at our pressure of 1 .2 mpa and our temperature of 50 degrees celsius, we have h2 equal to 278 .3 kilojoules per kilogram.
00:24
And at our evaporator temperature, we have h1 equal to 2 .78 .3 kilojoules per kilogram.
00:31
229 .02 kilojoules per kilogram.
00:36
Our compressor power is equal to m of refrigerator, which is our mass flow rate, times h2 minus h1.
00:48
But we're given p is equal to 3 .3 kilowatts of power.
00:52
So we plug in 3 .3 equal to m times 278 .3 minus 229 .02.
01:01
Solving through for m, m is equal to 0 .066 kilograms per second for a mass flow rate.
01:10
Then we'd like to find the refrigeration load.
01:17
From our ph chart, we get our condenser exit temperature equal to t saturated minus t sub, which is 46 .29 -5 or 4 .1 .29 degrees celsius.
01:32
And we have h -h3 equal to 110 .2 kilojoules per kilogram.
01:43
We also have h4 equal to h3.
01:47
Our refrigeration load, r, is nrm times h1 minus h4.
01:54
So we plug in 0 .066 times 229 .02 minus 110 .2.
02:02
And we get 7 .94 kilowatts...