Boiler basics and working principle _c_ boiler theory

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					Boiler basics and working principle (c) boiler principle

 basic knowledge of the boiler works

 Third Lecture: boiler parameters and technical and economic indicators
% boiler parameters D% A boiler parameters generally refer to the boiler capacity,
vapor pressure, vapor temperature and water temperature.
 industrial steam boiler with a rated capacity of evaporation, said. Rated evaporation
showed that the steam boiler in the rated pressure, steam temperature, boiler
efficiency and water required temperature, continuous operation must be guaranteed
when the maximum evaporation, often produce tons per hour steam capacity to
represent the unit t / h.
 hot water boiler with a rated capacity for the amount of that unit kw (kcal / h).
 boiler with a rated capacity of evaporation is also expressed in units of t / h.
 boiler steam pressure and temperature is the main steam superheater outlet valve
pressure of superheated steam and superheated steam temperature of boiler
superheater for free, with the main steam valve at the outlet, said saturated steam
pressure and temperature. The unit of pressure MPa (kpf/cm2), the temperature in
units of K or ℃.
 boiler feed water temperature is the temperature of water into the economizer, the
economizer of the boiler without fingering the boiler drum water temperature, units K
or ℃.
 industrial steam boiler feed water temperature is 20 ℃, 60 ℃, 105 ℃ third gear.
Boiler feed water temperature (in press) 150 ℃ , 170 ℃ , (pressure) 215 ℃ ,
(sub-critical) 260 ℃.
 boiler technical and economic indicators
 technical and economic indicators are generally boiler thermal efficiency of boilers,
boiler and boiler cost * of three could be expressed. High-quality boiler shall ensure
high thermal efficiency, low cost and can * run.
 1, boiler thermal efficiency
 boiler thermal efficiency is all the heat into the boiler was the effective use of the
percentage. The thermal efficiency of modern power station boilers are more than
90%. The thermal efficiency of industrial boilers (including hot water boiler) 55%
 boiler thermal efficiency is an important energy saving targets, the "quality grading
standards for industrial boilers" are clearly set out, first-class product boiler should
have a good energy-saving effect, the boiler thermal efficiency should be increased by
2%. Should be significantly superior product boiler energy saving effect of the
thermal efficiency should be increased by 4%.
 2, the boiler cost
 boiler costs with costs in general is an important economic indicator, said steel
consumption. Steel consumption is defined as the evaporation of the boiler unit
weight of steel used, unit t / h. Boiler parameters, loop mode, fuel type and boiler
components affect the structure of steel consumption rate. Boiler steam parameters,
high-capacity small, coal-fired, natural circulation, with tube-type air preheater and
the steel column structure can increase the rate of steel consumption; parameters of
low capacity, with boiler, oil or gas, using rotary air heater and steel reinforced
concrete structure can reduce the consumption rate.
 steel consumption rate of industrial boilers in the 5 to 6 tons of steel t / h or so; boiler
steel consumption is generally 2.5 to 5 tons of steel h / t range. In the boiler to ensure
safe, *, on the basis of economic performance should be to lower the rate of steel
consumption, particularly heat-resistant alloy steel consumption.
 3, the boiler can be * of
 boiler can be used * of the following three kinds of indicators.
 (1) continuous running time = twice the running time between maintenance (with
hours that).
 accident out of time
 (2) the accident rate =------------× 100%
 running total time + accident out of time
 run total time total time + standby
 (3) availability of =------------× 100%
 statistical time total time
 big test edited / center>

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