A boiler system having a series of boilers. Each boiler includes a shell having an upstream end, a downstream end, and a hollow interior. The boilers also have an oxidizer inlet entering the hollow interior adjacent the upstream end of the shell and a fuel nozzle positioned adjacent the upstream end of the shell for introducing fuel into the hollow interior of the shell. Each boiler includes a flue duct connected to the shell adjacent the downstream end for transporting flue gas from the hollow interior. Oxygen is delivered to the oxidizer inlet of the first boiler in the series. Flue gas from the immediately preceding boiler in the series is delivered through the oxidizer inlet of each boiler subsequent to the first boiler in the series.

Modern steam generators typically include a radiant section and a convection section. Due to differing performance requirements of the radiant and convection sections, the radiant section often has a round cross-section, while the convection section often has a rectangular cross-section. Previous designs utilized a target wall to effect the transition. An angled transition section is disclosed herein that substantially eliminates the target wall and/or the reverse target and provides a corresponding improvement in steam generator efficiency.

A boiler system for producing steam from water includes a plurality of serially arranged oxy fuel boilers. Each boiler has an inlet in flow communication with a plurality of tubes. The tubes of each boiler form at least one water wall. Each of the boilers is configured to substantially prevent the introduction of air. Each boiler includes an oxy fuel combustion system including an oxygen supply for supplying oxygen having a purity of greater than 21 percent, a carbon based fuel supply for supplying a carbon based fuel and at least one oxy-fuel burner system for feeding the oxygen and the carbon based fuel into its respective boiler in a near stoichiometric proportion. The oxy fuel system is configured to limit an excess of either the oxygen or the carbon based fuel to a predetermined tolerance. The boiler tubes of each boiler are configured for direct, radiant energy exposure for energy transfer. Each of the boilers is independent of each of the other boilers.

A boiler system for producing steam from water includes a plurality of serially arranged oxy fuel boilers. Each boiler has an inlet in flow communication with a plurality of tubes. The tubes of each boiler form at least one water wall. Each of the boilers is configured to substantially prevent the introduction of air. Each boiler includes an oxy fuel combustion system including an oxygen supply for supplying oxygen having a purity of greater than 21 percent, a carbon based fuel supply for supplying a carbon based fuel and at least one oxy-fuel burner system for feeding the oxygen and the carbon based fuel into its respective boiler in a near stoichiometric proportion. The oxy fuel system is configured to limit an excess of either the oxygen or the carbon based fuel to a predetermined tolerance. The boiler tubes of each boiler are configured for direct, radiant energy exposure for energy transfer. Each of the boilers is independent of each of the other boilers.

A method for producing steam while concurrently reducing emissions. The method includes combusting fuel and an oxidant stream having a high concentration of oxygen in a combustion zone having multiple combustion chambers and heat exchangers to produce a flue gas. The flue gas is subsequently cleaned in a dry flue gas cleaning chamber by contacting it with a dry adsorbent. In one embodiment, the method advantageously regenerates the dry adsorbent so that the dry adsorbent can be subsequently recycled back into the dry gas flue chamber.

A method for producing steam while concurrently reducing emissions. The method includes combusting fuel and an oxidant stream having a high concentration of oxygen in a combustion zone having multiple combustion chambers and heat exchangers to produce a flue gas. The flue gas is subsequently cleaned in a dry flue gas cleaning chamber by contacting it with a dry adsorbent. In one embodiment, the method advantageously regenerates the dry adsorbent so that the dry adsorbent can be subsequently recycled back into the dry gas flue chamber.

A steam generator has a heat exchange chamber with an upstream end and a downstream end. The steam generator further has a burner that injects primary reactants, including fuel and combustion air, into the chamber at the upstream end. A first branch of a once-through water line is located within the chamber downstream of the burner. A second branch of the once-through water line is connected in parallel with the first branch, and is located within the chamber downstream of the first branch. A fuel injector is arranged to inject staged fuel into the chamber at a staged location downstream of the first branch of the once-through water line.

Provided is a method for preparing steam, comprising: making a process waste heat fluid supplied from a plurality of waste heat sources flow into each of refrigerant evaporators having numbers corresponding to plurality of waste heat sources to vaporize a refrigerant through heat exchange; joining vaporized refrigerant streams from each of refrigerant evaporators to one integrated pipe; compressing refrigerant stream joined to integrated pipe in a refrigerant compressor; heat exchanging compressed refrigerant stream with water in a refrigerant condenser to prepare a condensed refrigerant stream and steam; and decompressing the condensed refrigerant stream by passing condensed refrigerant stream through a refrigerant expansion valve, followed by branching and circulating the condensed refrigerant stream to each of plurality of refrigerant evaporators, and further including transferring and compressing steam flowing out of refrigerant condenser to a steam compressor, and a system for recovering waste heat.

Provided is a method for preparing steam, comprising: making a process waste heat fluid supplied from a plurality of waste heat sources flow into each of refrigerant evaporators having numbers corresponding to plurality of waste heat sources to vaporize a refrigerant through heat exchange; joining vaporized refrigerant streams from each of refrigerant evaporators to one integrated pipe; compressing refrigerant stream joined to integrated pipe in a refrigerant compressor; heat exchanging compressed refrigerant stream with water in a refrigerant condenser to prepare a condensed refrigerant stream and steam; and decompressing the condensed refrigerant stream by passing condensed refrigerant stream through a refrigerant expansion valve, followed by branching and circulating the condensed refrigerant stream to each of plurality of refrigerant evaporators, and further including transferring and compressing steam flowing out of refrigerant condenser to a steam compressor, and a system for recovering waste heat.

A method for heating a heat exchange medium in a fluidized bed boiler (100), the method comprising burning first fuel (165) in a first furnace (162) of the fluidized bed boiler (100) to produce first flue gas (163); recovering heat from the first flue gas (163) to a heat exchange medium using a first heat exchanger (310); conveying the heat exchange medium from the first heat exchanger (310) to a second heat exchanger (320), of which at least a part is arranged in contact with a fluidized bed of the fluidized bed boiler (100); burning second fuel (175) in a second furnace (172) of the fluidized bed boiler (100) to produce second flue gas (173); conveying the heat exchange medium from the second heat exchanger (320) to a third heat exchanger (330); and recovering heat from the second flue gas (173) to the heat exchange medium using the third heat exchanger (330). A fluidized bed boiler (100) for performing the method. A loopseal heat exchanger (400) that is, when installed in a loopseal of a circulating fluidized bed boiler, configured to burn second fuel (175) in a second furnace (172) of the loopseal heat exchanger (400) to produce second flue gas (173); convey the heat exchange medium from the second heat exchanger (320) to a third heat exchanger (330); and recover heat from the second flue gas (173) to the heat exchange medium using the third heat exchanger (330).