To reduce the energy consumption of heating damper seal air

the flue gas before desulfurization was used to heat the seal air.The theoretical calculation method for seal air volume and heat transfer quantity was presented in detail.Take the desulfurization equipment on a 300 MW unit as the example

the configuration

investment and running cost of three seal air heating schemes(by gas-gas heat exchanger

electric heat exchanger and steam heat exchanger)was compared.The results showed that

the investment cost of gas-gas heating scheme was 4.2×105 yuan and 4.8×105 yuan higher than that of the electrical heating and steam heating scheme

respectively.However

compared to electric heating scheme

the gas-gas heating scheme can save running cost of 1.624×106 yuan per year and can recover the investment in 3months.Although the system is complicate and the investment cost is high

with low running cost

the gas-gas heating scheme has obvious advantages and is suitable for flue gas desulfurization equipments in all kinds of boilers.