h the original control unit.
For the purpose of experiments the boiler was fitted with
a flue gas analyzer unit. However, this unit is not sufficient
to be installed in a commonly sold product due to price and
size constraints. For that reason an effort is made to
eliminate this unit from the control algorithm. However,
oxygen level in flue gas needs to be available for the control
unit all the time. One proposed way of analyzer replacement
is installation of a wide-band lambda-probe for oxygen
measurement. It is commonly available and fulfils the
requirement for not to increase significantly the boiler’s
price. In the experiments has been also used analyzer to
detect CO concentration in the flue gas as a measure of
combustion quality. This unit will not be used in the real
application, however. Another possible solution can be
softsensing that would be able to estimate the required value
from another quantities that are readily available.