DE102004050465B3 - Fluid heating/vaporizing method for driving gas turbine`s power generation device, involves passing hot gas with dust via regenerators to hold dust in one regenerator, and passing cold and pure gas via other regenerator to form hot pure gas - Google Patents

Abstract

The method involves burning a energy source e.g. biomass, and passing hot exhaust gas that is generated by burning the source and laden with dust via a set of bulk material regenerators (B). The dust contained in the gas is retained by one regenerator. A cold and pure gas that is free from dust is passed via other regenerator, so that a hot pure gas is formed. The hot pure gas is passed via a heat exchanger (G) to heat/vaporize fluid. An independent claim is also included for a use of a bulk material regenerator for separating dust from hot exhaust gas.

Description

The The invention relates to a method for heating and / or evaporation of a fluid using hot dust laden exhaust gases. The invention further relates to a use of a bulk regenerator.

From the DE 44 26 356 A1 For example, a method is known in which hot waste gases laden with dust are formed by combustion of biomass. To separate the dust, the exhaust gases are passed through a filter. Subsequently, the heat of the hot exhaust gases is transferred in a heat exchanger to compressed air, which is then expanded via a gas turbine to the drive. The implementation of the proposed method requires a complicated to manufacture device in which both a filter for separating the dust and a heat exchanger are to be provided.

From the DE 43 17 947 C1 For example, a method of converting thermal energy of a gas into mechanical work is known. As gas is z. B. air is used, which is heated by means of a alternately connected in a turbine load regenerator. The regenerator is previously supplied with thermal energy by applying hot exhaust gases. Similar methods are for. B. from the JP 610 28 726 A (Patent Abstracts of Japan), the JP 620 85 136 A (Patent Abstracts of Japan) and the DE 39 31 582 A1 known. The foregoing methods require the use of dust-free hot exhaust gases from a combustion process to avoid damage and erosion on heat exchangers and turbines. Such exhaust gases can usually be provided only by a precisely controlled combustion of combustible gases. Flammable gases are not renewable as fossil raw material carriers. The price of fossil fuels is constantly increasing as resources become smaller.

From the DE 100 39 246 A1 For example, a method of converting thermal energy to mechanical work is known. In this case, hot exhaust gases formed by combustion of biomass are dedusted by means of a separate flue gas cleaning device and subsequently passed alternately through one of two regenerators. Once the regenerator reaches a predetermined temperature, it is switched into a turbine branch of a gas turbine and pressurized clean gas is passed through the regenerator. The hot and pressurized clean gas is released via a gas turbine to drive it. To carry out the known method, in turn, a special device for removing dust from the hot exhaust gas is required. Apart from that must be used to control the hot gas flow valves that withstand not only thermal loads but also pressure differences.

The DE 34 14 035 A1 discloses an apparatus for cooling a hot dusty exhaust gas. In this case, a heat storage mass of a regenerator is designed in its geometry so that dust deposits are effectively prevented therein. To separate the dust contained in the exhaust a wet scrubber is provided.

The DE 32 28 860 A1 describes a method for producing steam from hot exhaust gases. For this purpose, the dust laden hot exhaust gases are passed through a pressure vessel. The flow rate is chosen so that the dust laden hot exhaust gases cause no erosion. The dust is removed by means of a separate removal device.

From the DE 29 00 275 C2 is a device for reheating of pure gases after a flue gas scrubbing known. In this case, a regenerative heat exchanger is switched on the hot gas side between a dust collector and a gas scrubber in the line of a total flow of the raw gases.

Similarly, at one of the DE 32 38 941 C1 known method for the separation of dust provided an electrostatic precipitator.

At one of the DE 34 27 442 A1 known method flows through flue gas from a kiln in a preheater and a downstream waste heat exchanger. To ensure that the heat exchanger surfaces of sulfuric acid are not attacked, the temperature of the flue gas is maintained above the condensation temperature of sulfuric acid. Subsequently, the flue gas is a solids separation in a downstream separation unit, for. As an electrostatic precipitator or filter subjected.

The DE 100 35 710 A1 discloses a fossil-fueled power plant. In this case, a gas turbine is provided, which is operated with preheated air. For preheating switchable regenerators are alternately provided in the turbine load, with which part of the heat contained in the flue gas is recovered.

The DE 195 21 673 C2 relates to a method for regenerative exhaust air purification. Exhaust air contaminated with organic impurities is alternately passed through regenerators and thermally treated to destroy the organic impurities.

From the DE 42 38 652 C1 is a bulk regenerator known which can be flowed through radially to absorb thermal energy. Another bulk regenerator is from the EP 0 908 692 A2 known. In this case, stresses occurring in the annulus are reduced by an intervalwise discharge of bulk material. The discharged bulk material can be returned to the annulus via a transport tube.

From the DE 698 16 406 T2 a circulating regenerative heat exchanger is known, which is suitable for preheating combustion air in power plants.

So far the aforementioned methods, the conversion of thermal energy in concern mechanical energy by means of a gas turbine, the Thermal energy mostly by combustion of a combustible gas generated. The resulting exhaust gases are not loaded with dust. As far as the generation of thermal energy organic solid fuels are used to separate the dust a separate Device provided or measures are taken with which a Erosion of heat exchangers or clogging with dust. To can heat exchangers be particularly designed or it can be suitable flow rates or the like. Selected become.

task It is the object of the present invention to overcome the disadvantages of the prior art to eliminate the technology. It is intended in particular a method and a use can be specified with which to simple and inexpensive Way an effective warming and / or vaporizing a fluid from dust-laden hot exhaust gases possible is.

These The object is solved by the features of claims 1 and 18. Advantageous embodiments emerge from the features of claims 2 to 17.

• a) Verbrennen eines Energieträgers unter Bildung heißer und mit Staub beladene Abgase,
• b) wechselweises Durchleiten der dabei erzeugten heißen und mit Staub beladenen Abgase durch zumindest eine von mehreren Wärmespeicher- und Entstaubungseinrichtungen, wobei Wärme von den heißen Abgasen auf die Wärmespeicher- und Entstaubungseinrichtung übertragen und der im Abgas enthaltene Staub mittels der Wärmespeicher- und Entstaubungseinrichtung im Wesentlichen zurückgehalten wird,
• c) wechselweises Durchleiten von kaltem und im Wesentlichen staubfreien Reingas durch zumindest eine andere der Wärmespeicher- und Entstaubungseinrichtungen; so dass darin gespeicherte Wärme auf das Reingas übertragen und heißes Reingas gebildet wird, und
• d) Durchleiten des heißen Reingases durch einen Wärmetauscher zur Erwärmung und/oder Verdampfung des Fluids.

According to the invention, the following steps are provided in a method for heating and / or evaporating a fluid:

• a) burning an energy source to form hot and dust-laden exhaust gases,
• b) alternately passing the generated thereby hot and dust-laden exhaust gases through at least one of a plurality of heat storage and dedusting, wherein heat from the hot exhaust gases to the heat storage and dedusting transferred and the dust contained in the exhaust gas by means of the heat storage and dedusting substantially is held back
• c) alternately passing cold and substantially dust-free clean gas through at least one other of the heat storage and dedusting facilities; so that stored heat is transferred to the clean gas and hot clean gas is formed, and
• d) passing the hot clean gas through a heat exchanger for heating and / or evaporation of the fluid.

in the For the purposes of the present invention, the term "fluid" is a flowable material or a flowable substance Understood. It can be a liquid, such as water or a gas, act. The inventive method is used in particular for generating steam from water.

The inventive method allows a particularly high energy utilization of hot and dust laden Exhaust gases. In particular, it is no longer necessary to pass such exhaust gases through To lead a separate dedusting. The dedusting of the hot exhaust gas can surprisingly done in the regenerator. As a result, the dust contained in the dust is also heat content exploited. Also when passing clean gas through the previously by the hot ones Exhaust gas heated regenerator, the dust is effectively retained. The clean gas leaves the regenerator essentially dust-free. It can be an undesirable by Dust related corrosion and / or erosion in piping, heat exchangers and the like. Be prevented. Apart from that, that can essentially be dust-free clean gas also used without problem as combustion air become. The proposed method allows in particular in the Use of biomass as an energy carrier a particularly high energy utilization in the gas turbine and / or steam power process.

To an advantageous embodiment is provided that as a heat storage and dedusting a bulk regenerator used becomes. The exhaust gas is expediently substantially radially through a bulk regenerator absorbed bed directed. The dust is preferably retained in the bed.

According to a particularly advantageous embodiment, a portion of the bed is removed from an annular space of the bulk material regenerator to remove the dust and the dust is, for example, using a cyclone, separated from the bed. A generally suitable for carrying out the method according to the invention bulk regenerator is for example from the EP 0 908 692 B1 known. The known bulk regenerator is for carrying out the present invention however, still to be modified such that there is to be provided a device for separating dust from a transport gas used for transporting the bed. In the device may be conventional means for separating dust from a gas, such as a cyclone, filters, in particular electrostatic filters, a sieve and the like. The cleaned bed can be suitably then fed back to the annulus. The bed is expediently made of spherical bodies having an average diameter of less than 15 mm, preferably 4 to 8 mm. For example, the bodies may be made of alumina or the like. By such a bed, the flow velocity of the exhaust gases can be slowed by more than 80% with radial flow guidance. As a result, the dust settles in the bed.

The Clean gas is advantageously at a lower flow rate through the bed the at least one regenerator led as the hot and Dust laden exhaust gases. For this purpose, the clean gas flow branched and guided by several regenerators. This can be on easy way prevents being deposited in the clean gas stream in the bed Dust is carried away. The clean gas has after leaving the / Regenerators / en though a higher Temperature up, but is not contaminated with dust.

Further it has proved to be appropriate that the exhaust gas due to the passage through the heat storage and dedusting to a temperature of less than 100 ° C, preferably less than 80 ° C, cooled. Usually one is Inlet temperature of the hot Exhaust gas 800 ° C up to 900 ° C. The hot Exhaust gas is passing through the heat storage and dedusting with a cooling rate cooled from 1000 to 2000 K / m. By the extremely high cooling rate is advantageously a recombination of the hot exhaust gas contained pollutants, such as dioxins and furans, minimized or prevented. According to a further embodiment of the method according to the invention is the cooled Exhaust gas at least partially for preheating a combustion air used for combustion of the organic energy carrier. So that can the energy utilization further increased become.

To A further embodiment provides that the hot clean gas when passing through the heat exchanger to a temperature of less than 150 ° C, preferably less than 140 ° C, cooled. In this case, the cooled clean gas subsequently by means of preheating be conducted by condensate. This can be the cooled clean gas to a temperature of less than 80 ° C, preferably less than 70 ° C, further chilled become. After all that can be cooled down further Clean gas still used for the combustion of organic energy carrier become. The proposed process steps continue to contribute improved energy efficiency of the method according to the invention.

To A further embodiment provides that at least one Part of the transferred to the fluid thermal energy for driving a device for generating electricity and / or to maintain a predetermined operating temperature one in a heating network circulating liquid is used. In particular, the fluid may be in the form of vapor. The stored thermal energy in the steam, for example to carry out the Clausius-Rankine process, to drive steam engines, to execution Organic Rankine Cycle, Kalina Cycle or other processes be used.

Of the Steam can be condensed after the removal of energy. That allows one renewed evaporation of the condensate. In this case, the procedure can circulated become.

It has proved to be useful as pure gas and as an organic energy source a renewable energy source, in particular Biomass, to use. The aforementioned starting materials are inexpensive available.

To further requirement The invention relates to the use of a bulk material reactor for separating Dust from hot Exhaust gas provided. - In addition to the usual Function of a bulk regenerator, namely the storage of thermal energy, this invention can be another Function, namely that of a filter. As a result, the provision of the prior art known separate dedusting facilities are dispensed with, which usually one Regenerator upstream or downstream. The use according to the invention allows a considerable simplification in the construction of with solid organic fuels operated power plants, heat conduction networks and the like.

apart of which, with the proposed use, a significant increase the utilization of thermal energy contained in dust-laden hot exhaust gases Energy can be achieved.

following is an embodiment of Invention explained in more detail with reference to the single drawing.

In The figure schematically shows the essential components for carrying out a Steam power method shown in their functional context.

The reference symbol A denotes a fuel boiler which is suitable for burning solid organic energy carriers, for example biomass. Such a fuel boiler is for example from the DE 40 00 973 C1 known. An inlet provided on the fuel boiler A. 1 serves the task of fuel. Through an outlet 2 is discharged as combustion residue ash. From the fuel boiler A leads a first line 3 for discharging hot dust laden exhaust gases, which branches off in the course. By means of the first line 3 switched on slide 3a can alternately be applied to one of three downstream downstream regenerators B with the exhaust gas loaded with hot dust. The reference character C designates a suction blower which serves to generate a flow of the hot, dust-laden exhaust gases from the fuel boiler A through the regenerators B to a chimney E and a recirculation blower D. By means of the recirculation blower D, part of the exhaust gases can be supplied to the fuel boiler A via a second line 4. As a result, the temperature can be controlled in the fuel boiler and thus the formation of NO _x and / or the slagging counteracted.

A fresh air blower designated by the reference F conveys air via a third pipe 5 alternately through two of the regenerators B to a steam generator G. By the fresh air is passed through two of the regenerators B, the flow velocity can be slowed down and thus a recording of dust contained in the regenerators B can be prevented in a simple and efficient manner. The steam generated in the steam generator G passes through a fourth line 6 to a turbo-generator J. The cooled air emerging from the steam generator G passes through a fifth pipe 7 in a condensate preheater H, which in turn via a sixth line 8th is connected to a capacitor K. The condenser K is connected to the turbo-generator J for receiving the cooled vapor with a seventh conduit 9 connected. The reference symbol L designates a supply of water supply via the eighth lines 10 connected to both the condensate preheater H and the steam generator G. The cooled air leaving the condensate preheater H passes through a ninth pipe 11 in the fuel boiler A and serves as combustion air. To promote the air is in the ninth line 11 a fan M is turned on.

Instead of the turbogenerator J and the downstream capacitor K Alternatively, it is also possible the feedwater supply L and the steam generator G with a heat network FW for maintaining a given operating temperature in the heat network FW to pair.

The function of the device shown is as follows:
In fuel boiler A is through the inlet 1 fed biomass burned. The air required for combustion becomes the fuel boiler A via the ninth pipe 11 fed. The air gets over the second line 4 admixed a predetermined amount of exhaust gas. The formed during combustion in the fuel boiler A hot and dust-laden exhaust gases pass through the first line 3 depending on the selected position of the slide 3a through one of the regenerators B. The hot exhaust gases laden with dust are guided radially in the respective regenerator B through a bed received between a coaxial hot and cold grate. The thermal energy is transferred from the hot exhaust gases, in particular from the dust contained therein, to the bed. Furthermore, the dust contained in the hot exhaust gases is retained in the bed. From the respective regenerator B emerges substantially freed from dust cooled exhaust gas and is fed via the suction fan C substantially the chimney E. A partial flow of the cooled and dust substantially freed of exhaust gas is via the in the second line 4 switched recirculation blower D returned to the combustion.

The regenerators B are alternately charged with the hot dust laden exhaust gases. Once a predetermined temperature has been reached in the respective regenerator B, the hot and dust-laden exhaust gases by a corresponding change in the position of the slide 3a directed to one of the other of the regenerators B. Subsequently, air is passed through these regenerators B through one or more of the heated regenerators B via the fresh air blower F. The air absorbs the stored in the regenerators B thermal energy. The formed hot air passes over the first line 3 to the steam generator G. Steam generated in the steam generator G can be converted into electrical energy by means of the turbo generator J. The cooled vapor is condensed in a downstream condenser K. The condensate passes over the sixth line 8th in a condensate heater H, in turn, via the eighth lines 10 with a supply of water L is in communication. The condensate preheater H is acted on the input side with cooled air, which leaves the steam generator G. The air cooled further in the condensate preheater H finally passes over the ninth line 11 to the fuel boiler A and serves as combustion air.

Instead of of the turbo generator J, the hot steam generated in the steam generator G can also to maintain a given operating temperature in one heating network FW be used.

The With the proposed device feasible method is characterized through a high energy utilization. The high energy utilization is particularly due to the inventive use of bulk regenerators B achieved for the separation of dust from hot exhaust gases.

A

fuel boilers

B

regenerator

C

aspirator

D

recirculation

e

fireplace

F

Fresh air blower

FW

heating network

G

steam generator

H

condensate

J

turbogenerator

K

capacitor

L

Feed water supply

M

fan

1

inlet

2

outlet

3

first management

3a

pusher

4

second management

5

third management

6

fourth management

7

fifth line

8th

sixth management

9

seventh management

10

eighth management

11

ninth management

Claims (18)

Process for heating and / or evaporation a fluid with the following steps: a) burning a solid organic energy source under formation hotter and exhaust gases laden with dust, b) alternating passage the generated hot and exhaust laden exhaust gases through at least one of a plurality heat storage and dedusting facilities (B), whereby heat from the hot exhaust gases on the heat storage and dedusting device (B) and the dust contained in the exhaust gas by means of the heat storage and dedusting (B) substantially retained becomes, c) alternately passing cold and substantially dust-free clean gas through at least one other of the heat storage and dedusting means (B) so that heat stored therein transfer the clean gas and hot Clean gas is formed, and d) passing the hot clean gas through a heat exchanger (G) for heating and / or evaporation of the fluid. Method according to claim 1, wherein as heat storage and dedusting (B) uses a bulk regenerator becomes. Method according to one of the preceding claims, wherein the exhaust gas substantially radially through a bulk regenerator (B) absorbed bed is directed. Method according to one of the preceding claims, wherein the dust in the bed retained becomes. Method according to one of the preceding claims, wherein to remove the dust, part of the bedding from an annulus of the bulk material regenerator (B) and the dust, preferably using a Cyclones, from the bed is disconnected. Method according to one of the preceding claims, wherein the cleaned bed subsequently fed back to the annulus becomes. Method according to one of the preceding claims, wherein the exhaust gas due to the passage through the heat storage and dedusting (B) a temperature of less than 100 ° C, preferably less than 80 ° C, cooled. Method according to one of the preceding claims, wherein the cooled Exhaust gas at least partially for preheating a combustion air is used for combustion of the organic energy carrier. Method according to one of the preceding claims, wherein the hot Clean gas when passing through the heat exchanger (G) to a temperature less than 150 ° C, preferably less than 140 ° C, chilled becomes. Method according to one of the preceding claims, wherein the cooled Clean gas passed through a device (H) for preheating condensate becomes. Method according to one of the preceding claims, wherein the cooled clean gas during Passing through the device (H) for preheating condensate to a temperature of less than 80 ° C, preferably less than 70 ° C, is further cooled. Method according to one of the preceding claims, wherein the further cooled Clean gas used to burn the organic energy becomes. Method according to one of the preceding claims, wherein at least a portion of the thermal energy transferred to the fluid for driving a device (J) for power generation and / or maintenance a predetermined operating temperature of a in a heating network (FW) circulating fluid becomes. Method according to one of the preceding claims, wherein the steam is condensed after the energy extraction. Method according to one of the preceding claims, wherein is used as clean gas air. Method according to one of the preceding claims, wherein the clean gas with a lower flow velocity through the bed the at least one regenerator (B) is guided as the hot and Dust laden exhaust gases. Method according to one of the preceding claims, wherein as an organic energy source a renewable energy source, in particular biomass is used. Use of a bulk material regenerator (B) for separating from dust hot Exhaust.