Daikin R22, Руководство по проектированию трубопроводов для хладагента, Страница: 17 / 78

www.DaikinApplied.com 17 AG 31-011 • REFRIGERANT PIPING DESIGN
Equivalent Length for Refrigerant Lines
Table 5 and Table 6 on page 41 in Appendix 2 ( page 40 )
provide information for estimating equivalent lengths. The
actual equivalent length is estimated by calculating the path
length in feet (meters) that the piping will follow and adding
the pressure drops of the fittings and/or accessories along that
length. The tables provide pressure drops in equivalent feet of
straight pipe for fittings and accessories.
For example, in Table 5 , we see that a 7/8-inch (22 mm) long
radius elbow has a pressure drop equivalent to 1.4 feet (0.43
m) of straight copper pipe.
How to Determine Equivalent Length
Calculate the equivalent length of the liquid line for the
following condensing unit with DX air-handling unit:
The liquid line is composed of the following elements:
• 22 ft (6.7 m) of 1-3/8 inch (35 mm) piping
•
7 long radius elbows
• 1 filter drier
• 1 sight glass
•
1 globe type isolating valve
To determine the equivalent length for the refrigerant
accessories use Table 5 and Table 6 ).
Item Quantity Dimension, ft (m) Total, ft (m)
Long radius elbow 7 2.3 (0.70 m) 16.1 (4.90 m)
Filter-drier 1 35 (10.70 m) 35 (10.70 m)
Sight glass 1 2.5 (0.76 m) 2.5 (0.76 m)
Globe valve 1 38 (11.58 m) 38 (11.58 m)
Piping 1 22 (6.70 m) 22 (6.70 m)
Total 113.6 (34.64 m)
Liquid
Line