Document 5L7jDxw0M3ZOZKqebvQmndnY5
458
Chapter 24 -_________ - '
.
1945 Guide
Table 9. Pressure.Looses in -Dichlorodifluoromethane Suction Refrigerant Lines
Copper Pipe Actual O.D:
Inches.
Capacity Btu per Hour
- Pressure Drop in Pounds per Square Inch per 100 Fra 1 Refrigerant Temperature Deg F
.
1M
iH
m
-10
0
10
2.000
4.000 6.000 8.000 . 10,000.
0.3
13 . 2.8 4.8 7.4
0.3
1.0 . 2.2
3.8 5B
0.2
0B - 1.8
3.1 4B
12.000 14.000
16,000 18.000 20.000
10.5 14.0
8.4
11.0 14.5
6.8 . 9.1.
12.0
15.0
7.000
0.4 0.3 0.3
10.000
1.0 0.7 0.5
15.000
1.9 1.5 1.2
20.000 .3.3 2.6 2.1
25,000
5.0 4.0 3.2
35.000
45,000
60,000 70,000
9.7 15.8
7.7 6.2 12.6 . 10.0
' 10,000 15.000 20.000 30.000
40.000
0.3 0.2 0B 0.7 0.5 0.4
1.2 0.9 . 0.7
2.6 2.1 1.6 4.6 3.6 2.8
50.000
60,000 80.000
100.000
7.0 10.0
5.5 7.8 14.0
4.4
6B 11.0
30.000 .
1.6
40.000
2.7
. 50.000
4.2
60.000
6.1
70.000
8.7
1.3 1.0 2.1 1.7
3B 2.5 4.5 . 3.6 6.3 4.8
80.000 90,000 100.000 120,000
140.000
8.4 6.3 8.0 10.0..
50.000
0.7 0.5 0.4
.100.000
2.6 1.8 1.4
150,000
5.6
3.9
3:0
200,000
9.8 6.7 5B
250,000 300,000
350.000 400,000
14.8 - 10.3 14.5
. 19.5
8.0
ll'B 15.3
19.6
20 30 40 50.
0.2 0.2 0.7 0.6 1.5 > 1.2
2.6 2.1
3.9 . 3.3
0.1 . 0.1 0.5 0.4 1.0 0.9
IB 1.5 2B 2.3
5.6 7.6
9B 12.3 15.0
4.7
6.4 8.3 10.4 12.7
4.0 5.4
7.0 8.7
10.7
3.3 4.5
5.8 7.2
8.9
0B .0.5
1.0 1.7
2.7
0B 0.4
` 0.8 1.4
. 2.2
0.2 0.3 0.7 1.2. 1.9
0.1 0.3 . 0.6 1.0
1.6
5.1 8.4 14.8
4.3 7.0
. 12.2
3.6. . 5.9
. 10.2
14.0
3.0
4.9 . 8.6 11.7
0.2 . 0.1 . 0.1
0.1
0.3
0.3
0.2 -
0.2
0.6 0.5 0.4 0.4
1.3 1.1 0.9 0.8
2.3 1.9 1.6 1.4
3.5
5.0 8.7
13.5
2.9 2.5
4.2 .3.5
7.3 6.2
11.3
. 9.5
2.1
3.0 5.2
' 8.2
0.8 . 0.7
1.4 1.1 2.1 . 1.7 2.9 2.4 3.8 3.1
0.6 .
0.9 1.4
2.0 2.6
0.5 0.8 1.2 1.7
2B
4.9 4.0 3.3 2.8 6.2 4.9 4.1' 315 . 7.6 6.1 5.0 4.2
8.6 7.0 5.9 9.5 7.9
0.3 . 0.3 1.1 . 0.9 2.4 2.0 4.1 3.4
0.2
0.8 1.6 2.8- .
0.2
0.7 1.4
2.4
6.3 9.0 12.0. 15.3
5.1
7B . 9.7
12.5
4.2 6.0 7.8 10.0
*
' 3.6 5.0
6.7 8.5
^Length of tubing includes the average number of fittings.
by referring to the preceding discussion on Characteristics of Compression Systems. It will be noted that any'lowering of the suction pressure at the compressor lowers the capacity. Therefore, excessive pressure drop through the suction piping should be avoided. On the other hand, the suction line must not be made top large when using refrigerants which are soluble in oil, because under such circumstances the velocity of the re. turning refrigerant may become too low to carry back the entrained oil. Pressure drop in the discharge line also lowers the capacity of the system but not to the same extent as does the pressure drop in the suction line. The velocities of the. refrigerant in either suction or discharge lines must not be excessive' or noise will result. Velocities of 1000 to 2000 fpm are common in suction lines, and from 2000 to 3500 fpm are used in discharge
Refrigeration____________ "
'
450
. Table 9. Pressure Losses in . Dichlorodifluoromethane . Suction Refrigerant.5 Lines (Concluded) `
Copper Pipe ' Actual O.D. ' Inches .
Capacity Btuper Hour
Pressure Drop in Pounds per Square Inch per 100 Fra Refrigerant Temperature Deg F
.2H . '.
50.000 - 100.000
150,000 .200,000
250.000 300,000 350.000 400,000
450,000 500,000 550,000 600,000
-10
0,
10
20
30 '
40
50
. 0.2 0.2
0.1
0.1 . 0.1
0.1
0.1
0.7
0.6
0.5 ,
0.4
0.3
0.2
0.2-
1.6 1.2 1.0 0.8 0.6 0.5 0.4
2.8 . 2.1
1.7 .
1.4 .
1.1
0.9
0.7
4.3
3.4 ' 2.6
2.1
1.7
1.3
1.1
6.1 4.5 3.7 . 3.0 2.4 1.9 1.5
8.2 6.0 5.0 4.0 3.2 2.5 2.0
7.8 6.5 5.1 4B 3.3 2.7
7.7 6.4 , , 5.3 4.0 3.5 '
7.8 .
6.4
5.0 4.2
7.7 6.2 5.1
7.4 6B
200.000 .300,000
i.2 1.0 0.8 0.6 0.5 0.4 0.4 2.6 2.0 1.6 .1.3 1.0 ,0.8 0.7
3X
400.000
500,000 600,000 `
4.5- 3.4. 2.6 7.3 5/4 4.1
8.1 6.0
2.1 1.7 3.3 2.7 4.7 . 3.8
1.4 2B
'3.1
1.3
1.9 2.7
700.000
800,000 900.000
1,000.000
8.4 6.5 5.2 4B 3.5
8.6 . 6.8
5.5 '4.6
8.7 7.0 5.9
8.9 7B
3% y
--
300.000 400.000 500.000 / 600.000
700,000 800.000 900.000 1,000.000
1.100.000 1B00.000 1,300.000 1.400.000
1.2 2.0 3.2 4.6
6.4 8.7 '
0.9 1.6 2.5 3.6
4.9 6.4 8B
0.7 1.3 1.9 2B
3.8 4.9 6.2 7.7
9.4 '
0.6 1.0 . 1.6 ` 2.2
3.0 3.9 4.9 6.1
7.3 8.7
0.5 0.8 1.3 IB
2.5 3B 3.9 4.9
5.8 . 6.9 8.0 9.3
0.4 0.7 1.0 1.5
2.0 ' 2B
3B 4.0
4B 5.6 6.6 7.6
0.3 0.6 0.9 iB
1.7 2.2 2.7 3.3
4.0 4.8 5.6 ` 614 `
400.000 600.000 800,000 1.000,000 1,200.000
1,400.000 1.600,000 1,800.000 2.000,000 2.200,000
1.0 2.4 4.1 6.6
10.0
0.8 1.8 3.1 4.8 7.1
10.0
0.6 1.4 2.4 3.7 5.4
7.5 10.0
0.4 1.1 2.0 3.0 4.4
5.9 7.7 io.o
0.4 0.9 1.6 2.5 3.5
4.8 . 6.2 7.9 9.7
0B 0.7 . 1.3 2.0 2.9
3.9 5.1 6.4 7.9 9.5
0.3 0.6 1.1 1.6 2.4
3.3 ' 4.2 5.3 6.6 7B !
aLength of tubing includes the average number of fittings.
lines. Velocities in the discharge lines as high as 5000 fpm can only be used where the fittings and bends are all stream-lined as noise will other wise result.
The pressure drop in the liquid line affects the capacity of the expansion valve as the pressure drop across the valve is reduced by the amount of the pipe line drop. If the liquid line drop is sufficient to cause flashing (*.e. vaporizing) of some of the liquid refrigerant, a hissing noise in the fines and valves usually develops.
ICE SYSTEMS Cold water systems using ice as the cooling agent have been installed .