beautypg.com

Calculation example and explanation – REMKO PWW Series User Manual

Page 31

background image

31

The heating medium volume V

W

is calculated from:

V

W

= 860 x (litre/h)

t

W

= 90 – 70 = 20 °C

Q

L

= 37.6 (see solution under 2.))

This results in: V

W

= 860 x

= 1620 l/h

V

L

=

2400

V 4300

Calculation example and explanation

We reserve the right to make changes to dimensions and design in the interest of technical advances.

In the ratio V

L

to air

volume V (ratings table value), the
heat output factor can be determi-
ned from the “heat output factor
correction” f

Q

diagram.

The heat output from the ratings
table multiplied by the factor f

Q

results in the effective heat output
Q

L

(kW).

From the ratio V

L

to air volume V

(ratings table value), the air hea-
ting factor can be determined.
The air heating from the ratings
table (t

L2

- t

L1

) multiplied by the

air heating factor f

L

results in the

effective air heating.

For the calculation example, this results in:

Higher speed:
Air volume ratio

=

Heat output correction factor

f

Q

= 0.75

Effective heat output

Q

L

= 50.1 x 0.75 = 37.6 kW

Lower speed:
Air volume ratio

=

Heat output correction factor

f

Q

= 0,67

Effective heat output

Q

L

= 42.7 x 0.67 = 28.6 kW

Solution:

Heat output

Q

L

= 37.6/28.6 kW

For the calculation example, this results in:

Higher speed:
Air volume ratio

0.63 (see above)

Air heating factor

f

L

= 1.20

Effective air heating

t

L

= 28°C x 1.20 = 33.6°C [34°C]

Air outlet temperature

t

L2

= 34 + 15 = 49°C

Lower speed:
Air volume ratio

0.56 (see above)

Air heating factor

f

L

= 1.25

Effective air heating

t

L

= 30°C x 1.25 = 37.5°C [37°C]

Air outlet temperature

t

L2

= 37 + 15 = 52°C

Solution:
Air outlet temperature

t

L2

= 49/52°C

4. Heating medium resistance

V

L

3400

V 5400

= 0.63

= 0.56

2. Heat output Q

L

(kW)

3. Air outlet temperature t

L2

(°C)

For the calculation example, given from the diagram (see Page 31) is
the heating medium resistance for the unit type 80-3:

Dp

W

= 2.8 kPa

37.6

20

Q

L

t

W