Operating Instructions and Installation Instructions

LR, LRK, LR-NT, LRK-NT 21 - 32

We reserve the right to make changes to dimensions and construction 28 edition 30.10.2007

4.8. Correction values for different operating conditions

4.8.1. Flue gas temperature correction values LR, LR-NT

Average boiler water temperature tm °C 50 60 70 80 90 100

Flue gas temperature difference ∆t K - 16 - 8 ± 0 + 8 + 16 + 24

Excess air λ 1.10 1.15 1.20 1.25 1.30 1.35

Flue gas temperature difference ∆t K -6 -3 ± 0 +3 +6 +8

4.8.2. Modulation range

In chapter 4.5 modulation ranges are indicated for an average boiler water temperature of tm = 70°C.

Since the minimum power of the boiler is limited by the minimum allowable flue gas temperature, the modulation

range increases when the average boiler temperature increases. This is exemplary illustrated in the figure below

(example for oil operation with a minimum flue temperature of 120°C).

100

120

140

160

180

200

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

QN [%]

[°C]

tm = 80 °C

tm = 70 °C

(60 / 80 °C)

t = +8 °C

Mod 70°

Mod 80°

Flue gas temperature – Boiler power diagram, example for two average boiler water temperatures

4.8.3. Stand-by loss correction values

Average temperature difference *

Δtm

°C 30 40 50 60 70

Stand-by loss correction

ΔqB

% -40 -20 ± 0 20 40

* Average temperature difference = Average boiler water temperature minus ambient air temperature

Average boiler water temperature = Average of supply and return temperature