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. The upper furnace and the convection pass are also located next to each other, so that they share a common steam-cooled wall. There is no open pass between the furnace and the convection pass.

A device for closed-loop control of a plurality of state variables of a steam generator of a thermal power plant is provided. In order to achieve stable and exact closed-loop control of the plurality of state variables, a multi-variable control/controller controls the plurality of state variables and uses a linear quadratic controller for this multi-variable control/controller.

A device for closed-loop control of a plurality of state variables of a steam generator of a thermal power plant is provided. In order to achieve stable and exact closed-loop control of the plurality of state variables, a multi-variable control/controller controls the plurality of state variables and uses a linear quadratic controller for this multi-variable control/controller.

A method of recovering waste heat includes pressurizing a flow of working fluid and transferring heat from a hot gas stream to the flow of working fluid in at least two successively arranged heat transfer sections. At least some of the working fluid is converted to a superheated vapor by the transfer of heat, and passes through an expander to recover useful work. A portion of the flow of working fluid is directed along a branch after having passed through at least one of the heat transfer sections, and bypasses the expander and at least one of the heat transfer sections before being recombined with the working fluid that has passed through the expander. The total flow rate of working fluid can be adjusted to regulate the temperature of the hot gas stream downstream of the heat transfer sections, and the amount of fluid that bypasses along the branch can be adjusted to regulate the temperature of the superheated vapor.

A method of recovering waste heat includes pressurizing a flow of working fluid and transferring heat from a hot gas stream to the flow of working fluid in at least two successively arranged heat transfer sections. At least some of the working fluid is converted to a superheated vapor by the transfer of heat, and passes through an expander to recover useful work. A portion of the flow of working fluid is directed along a branch after having passed through at least one of the heat transfer sections, and bypasses the expander and at least one of the heat transfer sections before being recombined with the working fluid that has passed through the expander. The total flow rate of working fluid can be adjusted to regulate the temperature of the hot gas stream downstream of the heat transfer sections, and the amount of fluid that bypasses along the branch can be adjusted to regulate the temperature of the superheated vapor.

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.

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.

Presented are processes for the beneficial conversion of CO.sub.2 and other environmentally destructive compounds to their constituent parts by the application of thermal plasma containing activated species whereby the interaction of the plasma with the compounds and reactions of CO.sub.2 and H.sub.2 generate more environmentally friendly compounds comprising in part oxygen and hydrogen. The thermal plasma may be vibro-shear plasma generated by the superheating of either steam, gas or a combination of both.

The present invention relates to a system and a method for providing steam. In particular, the present invention relates to a steam delivery system comprising a thermal energy storage apparatus for heating a flow of feedwater to produce steam at a predetermined temperature and/or a predetermined pressure.

The present invention relates to a system and a method for providing steam. In particular, the present invention relates to a steam delivery system comprising a thermal energy storage apparatus for heating a flow of feedwater to produce steam at a predetermined temperature and/or a predetermined pressure.