摘要:
System and method for pre-startup or post-shutdown preparation for such power plants are disclosed which are subject to frequent startups and shutdowns, such as a solar operated power plant. The system and method introduces an auxiliary fluid flow to be circulated in an opposite direction to a direction of normal working fluid flow responsible for producing electricity. That is, if the working fluid flow in a first direction for operating the power plant, than the auxiliary fluid flows in a second direction, opposite to the first direction. The auxiliary fluid flows in the second direction for a predetermined time and at a predetermined conditions through a plurality of superheater panel arrangements of solar receiver former to activation of the working fluid circuit, as pre-startup preparation of the power plant, and after cessation of the working fluid circuit, as post-shutdown preparation of the power plant, to attain predetermined conditions in the superheater.
摘要:
A boiler is disclosed in which the furnace is divided into a lower furnace and an upper furnace. The lower furnace uses water-cooled membrane walls, while the upper furnace uses steam-cooled membrane walls that act as superheating surfaces. A steam-cooled circuit includes a steam separator, a primary superheater, and the steam-cooled membrane walls of the upper furnace. During start-up, a diversion path is opened that reduces dry steam flow through the primary superheater and increases dry steam flow through the steam-cooled membrane walls of the upper furnace. This protects the steam-cooled membrane walls from excessive thermal stresses during start-up.
摘要:
A boiler is disclosed in which the furnace is divided into a lower furnace and an upper furnace. The lower furnace uses water-cooled membrane walls, while the upper furnace uses steam-cooled membrane walls that act as superheating surfaces. A steam-cooled circuit includes a steam separator, a primary superheater, and the steam-cooled membrane walls of the upper furnace. During start-up, a diversion path is opened that reduces dry steam flow through the primary superheater and increases dry steam flow through the steam-cooled membrane walls of the upper furnace. This protects the steam-cooled membrane walls from excessive thermal stresses during start-up.
摘要:
A boiler is disclosed in which the furnace is divided into a lower furnace and an upper furnace. The lower furnace uses water-cooled membrane walls, while the upper furnace uses steam-cooled membrane walls that act as superheating surfaces. A transition section is present between the lower furnace and the upper furnace. The boiler is a high temperature sub-critical natural circulation boiler which is completely top supported. The lower furnace is supported through the transition section by the upper furnace.
摘要:
System and method for pre-startup or post-shutdown preparation for such power plants are disclosed which are subject to frequent startups and shutdowns, such as a solar operated power plant. The system and method introduces an auxiliary fluid flow to be circulated in an opposite direction to a direction of normal working fluid flow responsible for producing electricity. That is, if the working fluid flow in a first direction for operating the power plant, than the auxiliary fluid flows in a second direction, opposite to the first direction. The auxiliary fluid flows in the second direction for a predetermined time and at a predetermined conditions through a plurality of superheater panel arrangements of solar receiver former to activation of the working fluid circuit, as pre-startup preparation of the power plant, and after cessation of the working fluid circuit, as post-shutdown preparation of the power plant, to attain predetermined conditions in the superheater.
摘要:
A method of controlling stress in a boiler pressure vessel comprises limiting the diameter of a drum (10) of the boiler pressure vessel and preheating at least a portion of the wall (12) of the drum (10). Limiting the diameter of the drum (10) allows pressure in the drum (10) to be increased for a given mechanical stress. Furthermore, preheating the wall (12) of the drum (10) reduces peak thermally induced stresses in a material from which the drum (10) is fabricated.