Abstract

The invention relates to a method for recovering heat from flue gas and to a steam power plant. In the method, combustion air is preheated in a flue gas LUVO (10) by means of flue gases (FH) exiting a boiler (11) and feed water (W) entering the boiler (11) is preheated by means of steams bled from a steam turbine. A part of heated air (AH) having passed through the flue gas LUVO (10) is conveyed as recirculated air (AR) within preheated air (Ac) to be fed to the flue gas LUVO (10) and recirculated air (AR) is controlled to pass via at least one recirculated-air heat exchanger (8a, 8b), in which recirculated-air heat exchanger (8a, 8b) recirculated air (AR) is cooled by means of feed water entering the boiler.

IPC Classes  ?

• F01K 7/44 - Use of steam for feed-water heating and another purpose
• F22B 31/08 - Installation of heat-exchange apparatus or of means in boilers for heating air supplied for combustion
• F22D 1/38 - Constructional features of water and air preheating systems
• F23L 15/04 - Arrangements of recuperators

Abstract

The invention relates to a method for reducing greenhouse gas emissions in fuel applications of peat wherein peat material (6) is heated, thus partially pyrolyzing and partially coking the organic matter present in the peat material to yield components inert to biological decomposition processes. Components (10) separated in the gaseous form are utilized as a fuel, while peat coke (8) containing ash, and still in the solid form, is recycled back to the ground. The reactor is provided with reaction heat by passing flue gasses (11) generated in the combustion process (13) into the reactor. The method may also be applied to fuel applications of other biomasses.

IPC Classes  ?

• C10F 5/06 - Drying or de-watering peat combined with a carbonisation step for producing turfcoal
• C10B 53/02 - Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form of cellulose-containing material

Abstract

The invention relates to a combustion plant (10) which comprises a boiler (13) of solid fuel in which, in the combustion process, at the heat surfaces of the boiler (13) is directed a danger of corrosion from the components of combusted material causing corrosion. The boiler (13) comprises for combustion air a inlet fitting (14) and which steam boiler (13) comprises a steam generator (18) inside it from a steam generator circuit of which steam is transferred to a superheater (24) in the steam boiler (13) of the combustion plant via a fitting (23). From the superheater (24), superheated steam is transferred to a steam turbine (100) which is arranged to rotate an electricity generator (G) for generating electricity. The steam turbine (100) is two-piece comprising a low-pressure turbine section (100a) and a high-pressure turbine section (100b), whereby from the steam boiler (13) is conveyed from the first superheater (24) a fitting (25) first to the high-pressure turbine section (100b) from which is conveyed a bled steam fitting (26) back to the steam boiler (13) to a second superheater (27) located in it. From the superheater (27), superheated steam is transferred via a fitting (28) to the low-pressure turbine section (100a) of the steam turbine (100).

IPC Classes  ?

• F01K 7/22 - Steam engine plants characterised by the use of specific types of enginePlants or engines characterised by their use of special steam systems, cycles or processesControl means specially adapted for such systems, cycles or processesUse of withdrawn or exhaust steam for feed-water heating the engines being only of turbine type the turbines having inter-stage steam heating
• F22G 5/12 - Controlling superheat temperature by attemperating the superheated steam, e.g. by injected water sprays
• F23G 5/48 - Preventing corrosion