Functional Design of the mCCHP-RES System - Design for Micro-Combined Cooling, Heating and Power Systems - page 265

Table 9 Typical domestic pipe sizing [ 7 ]
Collector area (m 2 ) Flow rate (l/min) Pipe diameter copper

external (mm)

Pressure (mbar)

2 8.5

120 15 × 1

3 12.5

180 15 × 1

4 17

240 15 × 1

5 21

300 22 × 1

6 25

260 22 × 1

8 33

240 22 × 1

Table 9 shows the recommended pipe sizing for typical domestic systems.

(b) Finding the circuit curve This curve is de ned as the relationship between the

delivery head (total pressure required for ow.

Conceptually, any operation regime of the circuit is described by a particular
values set of the operating parameters and corresponds to a particular point on
the circuit curve. In concrete, at the required values of the operating param-
eters the required operation point is corresponding. Entire curve is analytically
described by the following equation:

fluid moving) and the volume

H Ges ¼ H geo þ H A ðÞ Pa ð 40 Þ

where:

H A ¼ H VL þ H VA P ðÞ 41 Þ

H VL ¼ R L ðÞ Pa ð 42 Þ

X f q v 2
2

H VA ¼ ðÞ Pa ð 43 Þ

H Ges Delivery head [Pa],
H geo Geodetic pressure difference [Pa],
H A Pressure loss along the hydraulic circuit [Pa],

H VL Pipeline pressure loss [Pa],

H VA Fitting pressure loss [Pa],

R Pipe friction resistance in Pa/m, given in diagrams like that presented in

Fig. 12 ,

L Pipe length [m],

f Resistance coef c to each element that is placed on the

circuit (be it component of system, device for measuring, control,
protection, or just a

cient, which is speci

fitting). For every element, this coef cient is a

technical feature whose value is given in the product data sheet.