Editing Boiler (section)

==Boiler efficiency==
There are two methods to measure the boiler efficiency in the [[ASME]] performance test code (PTC) for boilers ASME PTC 4<ref>{{cite web| title=ASME Performance Test Codes| url=https://www.asme.org/codes-standards/publications-information/performance-test-codes}}</ref> and for HRSG ASME PTC 4.4 and EN 12952-15<ref>{{cite web| title=EN 12952-15| url=https://www.en-standard.eu/din-en-12952-15-water-tube-boilers-and-auxiliary-installations-part-15-acceptance-tests/}}</ref> for water tube boilers:
# Input-output method (direct method)
# Heat-loss method (indirect method)

===Input-output method (or, direct method)===
Direct method of boiler efficiency test is more usable or more common.

: Boiler efficiency = power out / power in = Q × (Hg − Hf) / (q × GCV) × 100%

where
: Q, rate of steam flow in kg/h
: Hg, [[enthalpy]] of saturated steam in kcal/kg
: Hf, enthalpy of feed water in kcal/kg
: q, rate of fuel use in kg/h
: GCV, gross [[calorific value]] in kcal/kg (e.g., [[pet coke]] 8200{{nbsp}}kcal/kg)

===Heat-loss method (or, indirect method)===
To measure the boiler efficiency in indirect method, parameter like these are needed:
* Ultimate analysis of fuel (H<sub>2</sub>, S<sub>2</sub>, S, C, moisture constraint, ash constraint)
* Percentage of O<sub>2</sub> or CO<sub>2</sub> at flue gas
* [[Flue gas]] temperature at outlet
* [[Ambient temperature]] in °C and [[humidity]] of air in kg/kg
* [[Heat of combustion|GCV]] of fuel in kcal/kg
* Ash percentage in combustible fuel
* GCV of ash in kcal/kg