sauermann E INSTRUMENTS 1500, Operating & Maintenance Manual

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ANNEX D
Optional measures list:
MEASURE DEFINITION
λ, n Air index (defined as λ, sometimes also indicated as n ).
e
Air excess. Expressed as a percentage according to the formula in the appendix C, is
the ratio between the volume of air actually entering the combustion chamber and the one
theoretically needed.
Δ T
Differential temperature:
It is the difference between the smoke temperature and the air combustion temperature.
Qs (LHV)
Stack losses in relation to the Lower Heating Value:
It is the percentage of dissipated heat through the stack referred to the lower heating val-
ue (LHV)
Qs (HHV)
Stack losses in relation to the Higher Heating Value:
It is the percentage of dissipated heat through the stack referred to the higher heating
value (HHV)
η s (LHV)
Sensible efficiency in relation to the Lower Heating Value:
It is the burner efficiency calculated according to the UNI 10389-1 standard, as the ratio
between conventional heating power and the burner heating power. Among the combus-
tion losses, only the sensible heat lost with flue gasses is taken into account, thus ne-
glecting the radiation losses and incomplete combustion losses. This value is referred to
the Lower Heating Value (LHV) of the fuel and cannot exceed 100%.
The sensible efficiency value is to be compared against minimum efficiency stated for the
heating system performances.
η s (HHV)
Sensible efficiency in relation to the Higher Heating Value:
It is the burner efficiency calculated as the ratio between conventional heating power and
the burner heating power. Among the combustion losses, only the sensible heat lost with
flue gasses is taken into account, thus neglecting the radiation losses and incomplete
combustion losses. This value is referred to the Higher Heating Value (HHV) of the fuel
and cannot exceed 100%.
The sensible efficiency value is to be compared against minimum efficiency stated for the
heating system performances.
η c (LHV)
Condensation efficiency in relation to the Lower Heating Value:
Efficiency deriving from the condensation of water vapor contained in flue gases, calculat-
ed according to the UNI 10389-1 standard, and it is referred to the LHV.
η c (HHV)
Condensation efficiency in relation to the Higher Heating Value:
Efficiency deriving from the condensation of water vapor contained in flue gases referred
to the HHV.
η t (LHV)
η t = η s + η c
Total efficiency in relation to the Lower Heating Value:
Total efficiency. It is the sum of sensible efficiency and condensation efficiency. It is re-
ferred to LHV (Lower Heating Value) and can exceed 100%.