SK9195A3 - Method and device for the operation of a combined-process power station - Google Patents

Abstract

The invention concerns a method and device for the operation of a combined-process power station burning solid fuels, in particular lignite, the compressed hot air heated in a heat exchanger (7, 8) through which the exhaust gases from a boiler (1) pass being further heated by a separate combustion process (18) to give a hot-air/exhaust-gas mixture which is then fed to a gas turbine (28). The aim of the invention is to ensure that the power station can be operated efficiently and safely when burning solid fuels, in particular lignite. This is achieved by virtue of the fact that the hot air is further heated indirectly in a separate, series-connected, solid-fuel-fired combustion chamber (18) with facilities for liquid-ash removal and the exhaust gases from this series-connected combustion chamber are utilized, independently of or in conjunction with the exhaust air from the gas turbine, in the power-generation process or in separate processes to produce energy.

Description

Method and apparatus for operating a combined power plant

The invention relates to a method of operating a combined power plant with combustion of solid fuel, in particular coal, in which compressed hot air is heated in a heat exchanger, flue gas is supplied from a boiler, and indirectly heated to a gas turbine by a separate combustion chamber. The invention further relates to the operation of a combined power plant with solid fuel, in particular coal, wherein a separate pre-combustion chamber with an air heater is provided between the boiler provided with the heat exchanger and the gas turbine, the inlet side of which is connected to the boiler and the outlet side is connected to the gas. turbine.

into which it comes downstream and supplies the equipment by combustion

BACKGROUND OF THE INVENTION

The following processes are known in the combined power plants

Second

Third

4th

Combination

Combination heating m

Combination

Combined process with integrated process with partial full gasification of coal.

gasification and additional exhaust air boilers.

process with fluidized bed pressure furnace.

process with air heater heated by combustion of coal.

In a combined process with a heated air-fired air heater, many measures are known to improve the performance of this process and, for example, the arrangement of heat exchangers is known to increase its efficiency. Thus, heat for heating hot air for gas turbines in the ducts in which flue gases from the combustion chamber are conducted (DE-OS 32 03 082). The heated air is heated in a mixing and combustion chamber arranged in the air duct to which gas or oil is supplied and is supplied to the gas turbine as a mixture of hot air and flue gas (DE-OS 36 13 300). However, particularly in the case of lignite combustion, considerable dedusting costs (DE-OS 32 03 082) and the preparation of additional energy carriers (DE-OS 36 13 300) are required in order to achieve the real desired improvement in process performance and efficiency. For example, it is known to provide an upstream combustion chamber operated separately. with gas combustion, with an air heater, the inlet side of which is connected to the boiler, and the outlet side of which is connected to the gas turbine (JP 59046305). The pre-fired combustion chamber thus operated achieves the desired temperatures.

However, in order to achieve higher inlet temperatures in the gas turbine, high-value and specially prepared energy carriers such as gas are required. If solid fuel is used, hot gas must be cleaned. which, however, is not technically solved at the required temperatures.

It is therefore an object of the invention to provide an efficient and technically safe combined method of operating a power plant using solid fuel, in particular brown coal.

SUMMARY OF THE INVENTION

This task is fulfilled by the operation of the combined power plant with solid fuel combustion. in particular coal, in which the compressed hot air is heated in a heat exchanger to which flue gases from the boiler are supplied. and a separate pre-combustion chamber is indirectly highly heated and supplied to a gas turbine according to the invention, the principle being that the heated hot air is indirectly highly heated in the pre-combustion liquid ash withdrawal chamber operated with solid fuel and the flue gases from the pre-combustion chamber are used separately or together with the exhaust air from the gas turbine for energy use in a combined process or in separate processes.

The object of the present invention is to provide a plant for operating a combined heat and power plant, in particular coal, with a separate pre-combustion chamber with an air heater having an inlet side connected to the boiler and an outlet side connected between the heat exchanger-equipped boiler and the gas turbine. The invention relates to a gas turbine according to the invention which is provided with an upstream combustion chamber with a liquid ash extraction operated with solid fuel. and that the flue gas outlet of the precombustion chamber is connected separately or together with the exhaust gas air turbine outlet to the boiler and / or the fuel treatment device and / or the heat recovery device.

The solution according to the invention achieves the following advantages:

- the use of solid fuel, thereby saving high-value primary energy carriers,

- unambiguous separation of furnaces with the removal of solid and liquid ash by boiler and pre-combustion chamber design,

- an alternative to coal gasification, that is to say without purifying hot gas,

- use of modern combustion technology (pressure furnace, fluidized bed furnace and combinations thereof),

- avoiding corrosion and erosion of the gas turbine by solid particles,

- Increase efficiency using solid fuel by increasing gas turbine inlet temperatures (exploiting gas turbine development potential).

- substantial reduction of CO2 emissions,

- reduction of NOx emissions by dilution when introducing waste air from gas turbines into the boiler,

- the final concept of the design of the equipment.

- optimal execution of the process.

- optimal dimensioning of equipment components,

- possibilities of heat-force coupling,

- good operation and load behavior,

- use of waste gases for fuel drying,

- the use of existing habitats and infrastructure, as well as the possibility of retrofitting,

- the pre-combustion chamber must be designed exclusively for air heating.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to the accompanying drawings, in which: FIG. 1 shows a basic diagram of a combined process with an indirectly heated gas turbine and a steam / hot air boiler, heated coal, and an atmospheric pre-combustion chamber; FIG. Fig. 2 is a schematic diagram of a combined process with an indirectly heated gas turbine and a coal / hot air / steam boiler with a pressure pre-combustion chamber; 3 shows the branched-out fuel outlet for the pre-combustion chamber from the fuel conditioning device of the steam / hot air boiler and supplying flue gas from the pre-combustion chamber to the steam / hot air boiler or exhaust air from gas turbines, and Fig. 3 shows the air for the pre-combustion chamber and the steam / hot air boiler, including the addition of cold air; 4 shows the supply of flue gas from the pre-combustion chamber and the exhaust air from the gas turbine to the steam / hot air boiler; FIG. 5 shows the supply of the flue gas from the pre-combustion chamber and the exhaust air from the gas turbine to the fuel / fuel air treatment plant of the boiler; FIG. 6 shows the supply of flue gas from the upstream combustion chamber

to the boiler and circuit for on steam / hot i gas turbine, air s and closed air Fig. 7 basic scheme combined process with pressure heating steam boiler, 11akovou an upstream combustion

a chamber and a gas turbine downstream of it.

DETAILED DESCRIPTION OF THE INVENTION

The steam / hot air boiler 1 has a combustion chamber 2 with a fuel conditioning device 3, a fresh steam superheater 4 and an intermediate superheater 5, a combustion air supply system 6 as well as hot air air heaters 7, 8 (Fig. 1). . The fuel conditioning device 3 comprises a raw coal feed 9, a flue gas recirculation 10, a grinding machine 11, a coal powder line 12 and a pulverized coal burner 13. The combustion air supply system 6 comprises a fresh air blower (not shown), a cold air duct 14, an air preheater 15, a hot air duct 16, and an air mixer 17. The first air heater 7 (first stage) arranged above the combustion chamber 2 is formed as a heating surface from the tube bundle and the second air heater 8 (second stage) arranged in the combustion chamber 2 is formed as a wall heating surface. The superheaters 4, 5 are connected to a turbine with a steam turbine (not shown).

The precombustion chamber 18 comprises a third air heater 19 (third stage) and is provided with a fuel supply 20, a pulverized coal burner 21, a hot air duct 22, with an air mixer 23. the liquid slag withdrawal 24 as well as the flue gas outlet 25. The third air heater 19 is connected to the second air heater 8 of the steam / hot air boiler 7 and the other hot air duct 27 connected to the gas turbine 28, which is provided with the exhaust air duct 29. The gas turbine 28 is mechanically coupled to a generator 30 and a compressor 31 provided with a cold air conduit 32. and which is connected to the first air heater 7 of the steam / hot air boiler 7 via a compressed air line 33.

In the atmospheric pre-combustion chamber 18 (FIG. 1), the hot air duct 22 is connected to the hot air duct 16 for the air preheater 15. In the pressure pre-combustion chamber 18 (FIG. 2), the hot air duct 22 is connected to the hot air duct 26 downstream of the steam / hot air boiler 1.

The method of operation is as follows;

In the gas turbine process, the cold air drawn by the cold air line 32 is compressed in the compressor 31 and flows through the compressed air line 33 to the first air heater 7 and then to the second air heater 8 of the steam / hot air boiler 1. Subsequently, the hot air arrives through the hot air duct 26 into the upstream combustion chamber 18 and is indirectly heated to the inlet temperature to the gas turbine 28 in the third air heater 19. The hot air duct 27 is the hot air supplied to the gas turbine 28 and expanded there. The exhaust air is discharged for further use.

The temperatures of the hot air downstream of the boiler air heaters 7, 8 and the steam / hot air are determined by the materials used. For the first air heater 7 formed as a tubular air heater, steel is sufficient, while for the second air heater 8 arranged in the combustion chamber 2 as wall heating surfaces, steel or ceramic materials can be used as required. For the third air heater 19 contained in the upstream combustion chamber 18, only ceramic materials are considered. It is also possible to provide ceramic air heaters 8, 19 in the form of pipes, plates or even compact heated surfaces in the form of modules. In the production of hot air, the first air heater 7 and / or the second air heater 8 can also be omitted. Upon dropping them, the steam / hot air boiler 1 functions as a clean conventional steam generator. In this case, the compressed air line 33 is connected directly to the hot air line 26.

The third air heater 19 contained in the upstream combustion chamber 18 can also be made of several stages (not shown). In the steam turbine process, the steam / hot air boiler 1 burns coal dust, ground and dried in the fuel treatment plant 3, in the combustion chamber 2 releases heat and produces steam, which is superheated in the fresh steam superheater. The steam then flows into the high-pressure portion of the turbine (not shown) and then after expansion back to the steam / hot air boiler X. Subsequently, it is reheated again in the intermediate superheater 5 and leads again to the turbine for further expansion. The steam / hot air boiler 1 may be a coal powder boiler or a fluidized bed boiler (not shown). In the combustion air supply system 6, air is drawn in for the steam / hot air boiler 1 and for the atmospheric pre-combustion chamber 18 (FIG. 1) from a fan (not shown), and then through the cold air duct 14 through the air preheater 15 through ducts 16 and 16. 22, leads to pulverized coal burners 13, 21 at mixers 17 and 23. Flue gas from the steam / hot air boiler 1 is supplied to the air preheater 15 via the flue gas line 34. The waste gas from the air preheater 15 is led through the outlet line 35 to a flue gas cleaning device (not shown).

For the pressure pre-combustion chamber 18 (FIG. 2), the combustion air nevertheless branches off the hot air duct 26 and is led through the hot air duct 22 and through the air mixer 23 to the burners 21. However, this branch can also be made directly from the compressed air line 33 or downstream of the first air heater 7 (not shown). The fuel for the precombustion chamber 12 (FIG. 3) branches off from the fuel conditioning device 3 as a partial flow and from the coal powder line 12 is fed to the pulverized coal burner 20 via a fuel supply 20.

However, fuel preparation is also possible externally from the fuel conditioning device of another boiler in operation, from a separate fluidized bed steam dryer or from a coal dryer of a flue gas exhaust system or from a foreign source (not shown).

The flue gas from the pre-combustion chamber 18 (FIG. 3) is led through the flue gas outlet 25 to the steam / hot air boiler 1 or via line 36 mixed wholly or partly into the exhaust air from the gas turbine 28 conducted in the exhaust air line 29. As the combustion air for the steam / hot air boiler 1 and for the precombustion chamber 18 (FIG. 3), exhaust gas from the gas turbine 28 is used, which is discharged via the exhaust air line 29 to the hot air line 16, 22, a cold air mixer 37 is provided at the orifices for the purpose of adjusting the temperature. In this connection, the conventional pre-heater 15 of the combustion air is dispensed with and the flue gas from the steam / hot air boiler 7 is led through the outlet pipe 35 to a flue gas cleaning device (not shown). Combustion gases from the pre-combustion chamber 18 and waste. the air from the gas turbine 28 (Fig. 4) is led through the flue gas outlet 25 and the exhaust air duct to the boiler

1 for steam / hot air. The inlet can be made by common piping or by separate piping systems (not shown).

In this case, the steam / hot air boiler functions as a combined heat / steam boiler heated by waste heat.

The flue gases from the pre-combustion chamber 48 and the exhaust air from the gas turbine 28 (FIG. 5) are used for the grinding drying of coarse wet raw coal and through the exhaust gas outlet 25 or the exhaust air line 29 as well as the common line 38 are recycled. 10 flue gas. Mixing with the recirculated flue gas from the steam / hot air boiler 1 may occur. The inlet can be designed such that, beside the mixing operation, only the use of the flue gases from the steam / hot air boiler 7 or the flue gas mixtures from the pre-combustion chamber 18 and the exhaust air from the gas turbine 28 is possible.

The use of the flue gas from the pre-combustion chamber 18 and the exhaust air from the gas turbine 28 can be made in full or partial flow for the described options. A closed air circuit (Fig. 6) can also be formed by this. that the exhaust air from the gas turbine 28 is led through the exhaust air line 29 through the waste heat boiler 39 and through the suction line 32 to direct the cold air again to the compressor 31. In the waste heat boiler 39, the heat contained in the exhaust air from the gas turbine 28 is used to preheat the supply water and / or combustion air and / or to superheat the steam for the X / steam / hot air boiler or other separate process.

According to a further embodiment of the invention, the pressure pre-combustion chamber 18 in the combined process is integrated with the pressure steam boiler and downstream of the gas turbine 28 (FIG. 7).

The steam boiler X comprises a pressure furnace 2 with a fuel system 3, a fresh steam superheater 4, an intermediate superheater 5 and a combustion air supply system 6. The fuel system 3 consists of a conduit 12 for conveying the coal powder to its dispenser. The pulverized coal burner 13 or fluidized bed. The combustion air supply system comprises a compressor 31 for cold air ducts, a compressed air duct 33, an air heater 7, a hot air duct 16 and an air mixer 17. The steam boiler X is connected via a flue gas line 34 to a hot gas purifier 41, which is connected via a flue gas line 26 to an upstream combustion chamber 18. The flue gas heater 19 is located therein. Further, a fuel inlet 20, a burner 21 or a fluidized bed, a hot air conduit 16, an air mixer 23, a liquid slag exhaust 24 and a flue gas outlet 25 connected to the steam boiler 7 are provided in the upstream combustion chamber 18. The flue gas heater 19 and the gas turbine inlet 28 are connected to each other via the flue gas conduit 27 and the gas turbine outlet 2 is connected to the heat exchanger or the waste heat boiler 39 via the exhaust air line 29.

The waste heat boiler 39 comprises, in addition to the air heater 7, a heat exchanger 40 for preheating the supply water and / or converting it into steam, as well as an exhaust gas outlet pipe 35.

The method of operation is as follows:

In the steam boiler 1, heat is released in the pressure combustion chamber 2 by burning solid fuel and compressed flue gas is produced. The heat generated is used to produce steam and to overheat it in the superheaters 4, 5, and then the steam expands in the turbo engine (not shown). The resulting flue gas is led through a flue gas duct 34 to a hot gas scrubber 41, then via a duct 26 to the flue gas heater 19 of the upstream combustion chamber 18 and indirectly heated to the inlet temperature of the gas turbine 28. The cleaned highly heated flue gas enters the gas turbine 28. and are led through line 29 to the waste heat boiler 39. After the heat contained in the expanded flue gas has been transferred to the heat exchanger 40 and the air heater 7, the cooled flue gas is passed through the outlet conduit 35 to a chimney (not shown). The combustion air for the steam boiler 7 and the precombustion chamber 18 is sucked by the gas turbine compressor 31 through the cold air conduit 32, compressed and through the compressed air conduit 33 to the air heater 7 of the waste heat boiler 39. The heated combustion air then flows through the duct

Χ6 for directing hot air and with air mixer 17 to the pressure furnace 2 of the steam boiler χ. The combustion air for the pre-combustion chamber 16 is discharged as a partial stream from the hot air conduit 16 and via the hot air conduit 22 to the air mixer 23. The fuel for the precombustion chamber 18 can be removed as a partial stream (not shown) and is led through the fuel inlet 20 to the burner 21 or fluidized bed.

The flue gases from the pressure pre-combustion chamber 18 are led through the flue gas outlet 25 to the pressure furnace 2 of the steam boiler 1.

If the precombustion chamber 18 is designed as an atmospheric furnace, the flue gas may be fed to a waste heat boiler (not shown) and / or to an atmospheric pulverized-fuel boiler (analogous to FIG. 4) and / or to the fuel conditioning apparatus of the boiler ( analogously to FIG. 5) or to a separate device (not shown).

If an atmospheric pulverized-fuel-fired boiler X is used in place of the waste heat boiler (FIG. 7) (FIG. 4), it is possible to use the flue gas from the pre-combustion chamber 18 with the expanded flue gas gas turbine 28 analogously to the exhaust gas air. turbines 28 (FIGS. 4 and 5).

When introducing the flue gas from the pre-combustion chamber 18 and the expanded flue gas from the gas turbine 28 into the waste heat boiler 39 (FIG. 7) or into the boiler X (FIG. 4) or into the flue gas recirculation 10 (FIG. 5) is made by mixing through pipes 25, 29 through a common pipe 38 or separate pipe systems.

Claims (19)

PATENT A method of operating a solid fuel combustion, in particular hot air, heats incoming flue gases through a combustion chamber into a gas turbine (13) (28) combined in a boiler exchanger (1), and a power plant in which heat to heated hot air is drawn up in the upstream (18) liquid fuel by an indirectly high combustion chamber (18) with air from the combined 2. The method of heating a separate gas turbine is compressed and is pre-heated and supplied to a combustion plant operating with a solid chamber and the flue gas from a pre-process or 1 or 28 process or in separate together with waste energy recovery processes. according to claim 1, characterized in that the combustion air for the burners (21) of the boiler (1) and for the atmospheric operating pre-combustion is heated by a common pre-heater flue gas is supplied. Method according to claim 1, characterized in that the combustion air (15). with a boiler and an air chamber (18) into which for the burners (21) or 11-stage pre-combustion hot air. 4th Method according to claim 1, wherein the pre-combustion chamber (18) is discharged from the heated upstream combustion chamber (18) as a partial stream. Method according to claim 1, characterized in that the fuel for the pre-combustion chamber (18) is produced in a separate fuel treatment plant. A method according to claim 1, wherein the fuel is removed from the boilers and the power plant. which is in operation. A method according to claim 1? use i ú ú 9th that the spa1 i ny z A method according to claim 1 for the apparatus The method according to the preceding claim, in the combustion chamber, characterized in that the preliminary combustion chamber (3) is used to treat the fuel of the boiler (1). of claim 1, wherein the flue gas is admixed to the waste gas 18) sa 18) with air gas turbine (28). Method according to claim 1, characterized in that the exhaust air from the gas turbine (28) is used as combustion air for the boiler (1) and / or the pre-combustion chamber (18). Method according to claim 1, characterized in that the exhaust air from the gas turbine (28) is introduced into the boiler (1). 1.2. Method according to claim 1, characterized in that the exhaust air from the gas turbine (28) is used for the fuel conditioning device of the boiler (1). 13th process by claims 1 and 7 up to 12, v y z - c i s and you m that is produced mixture spa1 í n and waste air. 14th process by Claim 1 v y z n a č u it is t ý m. The exhaust gas from the pre-combustion chamber (18) and / or the exhaust air from the gas turbine (28) is used for a separate fuel treatment device. Method according to claim 1, characterized in that the exhaust gases from the upstream combustion chamber (13) and / or the exhaust air from the gas turbine (28) are used for separate recovery of waste heat. Method according to claims 1 and 7 to 15, characterized in that. 3. The method according to claim 1, characterized in that cold air is mixed into the flue gas and / or the exhaust air from the gas turbine (28). Method of operating a combined power plant with a pressure-heated boiler (1) and combustion of solid fuel, in particular brown coal, in which the combustion gases from the boiler (1) are cleaned, odde1enou ballast ohr i evaj ú and bring in y z n and < 5 -3 boiler (1: ) in a separate WITH go away ahom! liquid ash, indirectly highly heated, and the chambers (18) are segregated by a vapor chamber (18) high into the gas turbine (28), by cleaning the flue gas of the pre-combustion chamber (18) operated with solid fuel, the flue gas from the pre-combustion or together with waste gas from the gas turbines (28) are used for energy in a combined process or in a separate process. Method according to claim 17, characterized in that the flue gases from the upstream combustion chamber (18) are fed to the waste heat boiler and / or to the boiler (1) and / or to the fuel conditioning device (3) of the boiler (18). 1) and / or to a separate installation. Method according to claim 17, characterized in that the combustion air for the upstream combustion chamber λ is discharged as a partial combustion air flow 20 for the boiler (1) Method according to claim 17, characterized in that the fuel for the upstream combustion chamber (18) is discharged from the fuel supply (3) to the boiler (1). Method according to claim 17, characterized in that the flue gases from the upstream combustion chamber (18) are returned to the boiler (1). Apparatus for operating a combined power plant with combustion of solid fuel, in particular coal, wherein a separate pre-combustion chamber (18) with an air heater (19) is arranged between the boiler (1) provided with the heat exchanger (7, 8) and the gas turbine (28). whose inlet side (26) is connected to the boiler (1), and whose outlet side (27) is connected to the gas turbine (28), characterized in that it is provided with an upstream combustion chamber (18) operated by liquid ash solid fuel, and that the flue gas outlet (25) from the pre-combustion chamber (18) is separately or together with the exhaust air outlet (29) from a gas turbine (28) combined with boiler (1) and / or so device (3) on treatment fuel and / or with device for use of heat. 23. Equipment by claim 22, s listen characterized in that the boiler (1) is designed as a combined steam, hot air and waste heat boiler. Apparatus according to claim 22, characterized in that the combustion air duct (22) for the atmospheric operated burners (21) of the pre-combustion chamber (18) is connected to the combustion air supply duct (6) of the boiler (1). Apparatus according to claim 22, characterized in that the combustion air duct (22) for the pressure pre-combustion chamber (13) is connected to the hot air duct (26). Device according to claim 22, characterized in that. characterized in that the fuel supply (20) to the pre-combustion chamber (18) flows into the fuel conditioning device (3) of the boiler (1). List of boiler reference numbers incineration a chamber, pressure furnace 2 e Fuel conditioning system, fuel system player 4 fresh steam intermediate superheater 5 combustion air supply system 6 first air heater 7 second air heater 8 air supply 9 raw coal feed back 10 flue gases grinding st swarm 1 1 pipeline e 12 on leadership e coal powder burner 13 on the powder uh 1 i e pipeline i e 14 on leadership e cold air air preheater 15 duct 16 for guiding hot air air shaker 17 air pre-combustion chamber 18 third air heater 19, flue gas inlet 20 fuel burner 21 pulverized coal conduit 22 for guiding hot air air shaker 23 air exhaust 24 liquid slag outlet 25 flue gas duct 26 hot air, flue gas hot air duct 27 gas turbine 28 exhaust air duct 29 generator 30 compressor 31 cold air duct 32