摘要 |
A furnace of a boiler for a power plant includes an outer water tube section adapted to receive water from the outside and heat the water into hot water (including steam); and an inner water tube section adapted to receive water from the outside and heat the water into hot water (including steam) while allowing the water to be moved upwardly. The outer water tube section is formed in a shape gradually increasing or substantially uniform in diameter from the bottom toward the middle portion M, and gradually decreasing, increasing and decreasing again in diameter from the middle portion M toward the top, and the inner water tube section is formed in a shape gradually decreasing and increasing in diameter from the bottom toward the middle portion M, and gradually decreasing, increasing and decreasing again in diameter from the middle portion M toward the top. |