With the rising costs of energy and concerns about global warming, it is imperative that countries adopt the most efficient energy conservation measures and technologies. Waste heat recovery is a good way to make coal fired boiler running efficiency. On the one hand, If we are to share commercial energy equitably across all sections of society, it is necessary to conserve energy and use it efficiently. On the other hand, Industries can become globally competitive when their production process consumes the least amount of energy.
Condensate recovery in coal fired boiler
Steam condenses after giving off its latent heat in the heating coil or the jacket of the process equipment. A sizable portion (about 25%) of the total heat contained in the steam leaves the process equipment as condensate (hot water). If this hot condensate is returned to the boiler house, it will reduce the fuel requirements in the boiler. Further, in most cases, the boiler water has to be chemically treated to prevent or reduce scale formation, whereas condensate is almost entirely pure water, which needs no treatment. With a high share of the condensate returning to the boiler house, the expenses involved for water treatment can therefore be reduced by an appreciable amount.
Flash steam recovery for coal fired boiler
Flash steam is produced when high pressure condensate is flashed in an enclosure to produce low pressure steam, and can be used for heating application. The specially designed enclosure is called a flash vessel, which is available with most steam equipment suppliers. The flash steam quantity can be calculated by the following formula with the help of steam tables:
Flash steam is calculated in % = S1 – S2) / L2
3.9.7 Flash steam recovery
3.9.8 Reducing the work to be done by steam
S1 is the sensible heat of higher pressure condensate,
S2 is the sensible heat of steam at lower pressure (at which it has been
and L2 is the latent heat of flash steam (at lower pressure)
Coal fired steam boiler is used for generating power as well as for process heating applications in industries such as sugar, paper, fertilizer, refineries, petrochemicals, chemicals, food, synthetic fiber and textiles. Using waste heat recovery technology in coal fired boiler can help enterprises improve efficiency and save money. Meanwhile, it is a good way to make the life of boiler longer.