Gas prodn. for gas turbine operation - in combined gas and steam turbine power station

The invention relates to a method and an apparatus for carrying out the Process for the generation of gases for operating a gas turbine in a combined cycle power plant, in which fine-grained to dust shaped carbon under a pressure <1 and a temperature of <1000 ° C with air or oxygen-enriched air or pure oxygen alone or with each recirculated exhaust gas mixed in a combustion chamber is almost completely burned becomes a combustion gas consisting essentially of CO₂ and water vapor and when air is used also consists of nitrogen, and then cleaned at least of dust including alkali metal compounds in succession a gas turbine and a heat recovery steam flows through, in the water for Operating a steam turbine at one or more pressure stages preheated, is evaporated and superheated.

By publication DE 27 33 029 A1 a system is energy recovery from solid fossil fuels and in particular fiber-rich fuels, particularly stone charcoal made famous. The fuel is in a melting chamber boiler burned under pressure, and at the same time, a part of combustion heat to the Evaporation of the in melting chamber boiler in the steam cycle water used. The donating a portion of its heat to the melting chamber boiler Flue gas is then purified in a cyclone of coarse dust before in a gas / gas heat exchanger by cold, purified flue gas to 300 ° C is cooled and fed to a further cleaning and cooling, the Flue gas by adding water (water wash) by Cl, F, NO_x cleaned and is cooled to 118 ° C. The cooled and cleaned flue gas is at closing the gas / gas heat exchanger by the hot, unpurified flue gas reheated and supplied to a gas turbine.

The disadvantage is evident in this system that the decoupling of Burn tion heat from the flue gas (flue gas) to the working medium Water / steam lower flue gas temperatures at the melting chamber boiler outlet result and hence lower gas turbine inlet temperatures for a Gas / gas heat exchanger can be achieved. The efficiency of this system is be reduced because of the saturation of the flue gas by cooling water. The Gas turbine in accordance with the disclosed prior art only with a Gas turbine inlet temperature operated by z. B. 851 ° C.

By document DE 37 20 963 A1 a method and a device for Deposition of ash from the resulting from the combustion of coal gas become known in which or in which a combustion gas by Burn drying of the coal is produced under pressure and in which the liquid in the form of ash Droplet is suspended by at least one arranged in the combustion chamber ceramic, porous, gas-permeable filter element is guided whose Hauptbe constituents Al₂O₃, SiO₂, MgO and / or ZrO₂ are.

In this known method and this known device is to be pieces that such filter elements for flue gas temperatures of 1200 ° C to 1700 ° C neither practical nor proven field-tested.

Through EP 0402972 A1 describes a filter element made of SiO₂, Al₂O₃ and or ZrO₂ known as well as an organic binder for filtering Müllver brennungsabgasen the temperature range from 300 ° C to 1000 ° C and to avoid tion is used by dioxin formation.

By publication DE 29 34 858 A1 is a gas turbine plant with pressurized fluidized schichtfeuerung become known in which, by a line, the two coaxial comprising tubes through the inner tube of hot gas from the combustion chamber for Gas turbine and in the cylindrical annular space between the outer and inner Pipe air is fed from the compressor to the combustion chamber. This arrangement allowed light cooling of the inner tube through the cool air and thus compliance the strength values ​​of this tube and a transfer of the flue gases from the Combustion chamber to the gas turbine with the lowest possible heat loss, since the inner Pipe is internally insulated and heat loss to the air largely prevented becomes. Since the combustion chamber a Pressurised is used to Exhaust for Gasturbinenbeaufschlagung of max. 800-900 ° C are obtained. at However, these low temperatures can not with a gas turbine plant high efficiency operate.

By DE-AS 10 30 359 is a "between engine and Zwi schenerhitzer a thermal power plant arranged interconnector "bekanntge been that a coaxial heat exchange between the hot (heated) and cold represents (to be heated) Zwischenerhitzerdampf. A suitably trained Pipeline can also be used in a gas turbine plant, ie from a gas turbine escaping, cooled gas from a gas turbine in a entering, heated gas is heated. Purification of the cooled Gas turbine gas and reheating of this gas after cleaning by the heated gas before introduction into the gas turbine is not provided.

By DE-OS 23 33 087, in turn, a combustion chamber with vortex become known bed, in which a fuel is combusted and the generated Combustion exhaust gas is supplied through a conduit of a gas turbine. The Combustion gas is partly with cold air in indirect heat exchange, further is admixed to the combustion gas and air, heated air. As with the A gas turbine plant according to DE 29 34 858 A1 may also known at this Plant only a combustion gas at a temperature up to max. 950 ° C of supplied to the gas turbine and thus no high efficiency can be achieved.

Further, through the publication DE 37 42 892 A1 a gas turbine plant with a Combustor, and a recuperator as a heat exchanger for the compressed Ver combustion air become known, wherein the recuperator annular and its longitudinal axis is coaxial with the longitudinal axis of the combustion chamber. A Rei acceleration of the cooled gas and subsequent reheating by the Raw gas before introduction into the gas turbine is not provided.

Generic systems are further characterized by the publication "New power plant concepts for brown coal "by H. Bergmann u. J. Ewers from VGB Power Plant Technology (70) 1990 Issue 5, Pages 399-405 become known. contain the generated gases harmful substances that would damage the gas turbine is therefore a Gas cleaning necessary. Since effective cleaning of such hot, pollution-laden gases with temperatures above the permissible entry temperatures of modern gas turbines that is <1200 ° C is hardly feasible, should the Temperature of the gases are reduced to a level of approximately 650-950 ° C to the to carry gas purification with known and proven methods. This Temperature level is especially for the dry additive method (Desulphurization by Kalkstaubeindüsung) and Selectiv noncatalytic Redudion- SNCR process (reduction of nitrogen oxides with ammonia without catalyst) crucial. To achieve this temperature level, is generally heat coupled to a steam power process or a very high excess air hazards.

A disadvantage of the known processes, heat to a steam process decouple or to drive a high excess air, the loss of efficiency by heat transfer to the steam process with a relatively low temperature or by the reduced gas turbine inlet temperature at high excess air and the increased exhaust gas losses. Further, the coupling of gas turbine and Abhitzekesselbetrieb adversely.

has, according to the climate debate, environmental protection and resource conservation the not inconsiderable increase in the efficiency by the proposed Method and the proposed device large in recent years Gained importance.

The object of the invention is a method of the type described above as well as the to provide corresponding apparatus in which avoids the disadvantages and be a decisive improvement in the efficiency in the generation electric power from coal is achieved. This object is solved by the features of claims 1 and 6. FIG.

Advantageous embodiments of the invention are the sub-claims to remove.

The inventive measures are compared with the following advantages the known prior art obtained:

<ul><li>1. Higher clean gas temperatures (1200-1400 ° C) can be achieved, so that Gas turbines with higher inlet temperatures and correspondingly higher Efficiency can be operated.</li><li>2. The need for gas purification, with respect to the permissible inlet temperature the gas turbine lower temperature (650-950 ° C) is obtained exclusively by Raw gas-clean gas heat exchange and mixing a cooling gas consisting of recirculated exhaust gas or a gas similar to the oxidant, without leaving coupling of heat reaches the heat recovery steam generator; characterized the entire used fuel performance in the gas turbine and the heat losses are against lower than the prior art. The efficiency of the entire system is improved.</li><li>3. The gas turbine can be independent from its own chimney Waste heat boilers are operated.</li><li>4. The required anyway innerliner of the vessels and connection pipes is used as a heat exchanger and the temperature of the Pressure vessel and connecting pipe walls at the same thickness of insulation reduced. Under certain circumstances, a separate heat exchanger (pos. 15 in <b>Fig.</b> 2) be waived.</li></ul>

The invention is based on the description and the <b>Fig.</b> 1 and 2 explained in more detail.

<b>Fig.</b> 1 shows a combined gas and steam turbine power plant, the plants, the complex <b>31-37</b>, Namely compressor <b>31</b> for exhaust gas compressor <b>32</b> for air or with Oxygen enriched air or pure oxygen, combustion chamber <b>33</b>, heat exchangers <b>34</b>, Gas purification <b>35</b>, Gas turbine generator <b>36</b> and waste heat steam generator including steam turbine and generator <b>37</b> includes.

<b>Fig.</b> 2 shows the system components <b>33</b>. <b>34</b> and <b>35</b>Wherein fine-grained to dusty Coal under pressure, z. B. 15 bar, enriched with air or oxygen Air or with pure oxygen alone or in each case with a recirculated exhaust gas combustion chamber <b>27</b> a fuel, oxidant and Abgasrezirku lationseintritt <b>11</b> is supplied and combusted in the latter. Combustion takes it either at a temperature held at which the ash remains solid or molten can be deducted. The combustion temperature can be obtained by the choice of the air Excess oxygen and / or the exhaust gas recirculation can be adjusted and / or.

The combustion chamber <b>27</b> is cyclonic, whereby much of the ash abgeschie to and through the ash outlet connection <b>14</b> can be deducted. If the Combustion temperature in the combustion chamber <b>27</b> above the ash melting point, the combustion gas at Rohgasaustritt is <b>12</b> the combustion , space <b>27</b> by admixture via the port <b>26</b> of recirculated exhaust gas or a gas similar to it is used for combustion, to a temperature cooled below the ash melting point to slagging of the subsequent To avoid line and the heat exchanger. Then flows Combustion gas = raw gas in both cases (solid or molten ash in the Combustion chamber) through the first connection designed as a heat exchanger management <b>2</b> and - if necessary - on the raw gas <b>16</b> a heat exchanger pressure vessel <b>3</b> through the heat exchanger <b>15</b>In said Heizflächenraum <b>22</b> of Heat exchanger pressure vessel <b>3</b> to cool the raw gas and for heating the clean gases is arranged.

The raw gas leaves the heat exchanger pressure tank <b>3</b> over the Rohgasaustritt <b>17</b> and flows over the insulation with only one <b>7</b> provided second interconnector <b>4</b> and the crude gas inlet <b>18</b> in the gas cleaning pressure vessel <b>5</b> one Gas cleaning member <b>35</b>Wherein the by the heat transfer to the clean gas already cooled raw gas through the pipe <b>30</b> recirculated exhaust gas or a gas similar to as it is used for combustion, is mixed, so that it in a Temperature between 650 to 950 ° C is cooled. At this temperature, the Crude gas with known methods, such as. z. B. cyclones, ceramic filter candles<b>24</b> etc., be dusted (including alkali metal compounds) and further by also known methods, eg. as dry additive method, ie by spraying Lime desulfurization or z. B. by Selective noncatalytic reduction SNCR Method, ie to be freed by injecting ammonia, nitrogen oxides. These Gas purification procedures are in the gas cleaning pressure vessel <b>5</b> the gas cleaning supply part <b>35</b> arranged from about quitting <b>20</b> Fly ash and other Residual materials, such. As gypsum, can be deducted. The feeding of the additives is carried out via the port <b>28</b>, The purified combustion gas flows = Clean gas through the clean gas outlet <b>19</b> and only with isolation <b>7</b> provided third connecting line <b>6</b> and the clean gas inlet <b>23</b> back to the heat exchanger pressure vessel <b>3</b>, The clean gas then flows - if needed - the Wärmetau shear <b>15</b> and / or designed as a heat exchanger, one behind the other composites NEN channels <b>10</b>. <b>9</b> and <b>8th</b>Wherein the third channel <b>10</b> in the heat exchanger pressure vessel <b>3</b>, The second channel <b>9</b> in the first connecting line <b>2</b> and the first channel <b>8th</b> in the combustion chamber pressure vessel <b>1</b> lies. The clean gas increases from the uncleaned combustion gas = raw gas heat on and leaves the internal chamber pressure vessel <b>1</b> on the clean gas outlet <b>13</b> the permissible gas turbine inlet temperature. The clean gas then flows successively through the gas turbine<b>36</b> in <b>Fig.</b> 1 and the heat recovery steam generator <b>37</b> in <b>Fig.</b> 1, in the water for operating a steam turbine to one or more pressure steps (in <b>Fig.</b> 1 is a possible Circuit is shown with 3 pressure stages) preheated, evaporated and superheated. It and heat for heating purposes could be extracted.

After the heat-recovery boiler, a part of the exhaust gas through one of the gas turbine <b>36</b> driven compressor <b>31</b>, please refer <b>Fig.</b> 1, to the mentioned above or stub admissions <b>11</b>. <b>26</b> and <b>30</b> be recycled. The radical may - if this is required or has not happened yet - purified in a known manner on permitted levels of emissions be and leaves the power plant via a chimney. If as the oxidizing agent pure oxygen is used, generated as waste gases - as already mentioned - a Gas mixture, which almost entirely of CO₂ and water vapor is. With appropriate further cooling first water vapor condenses and eventually will also the CO₂ with the remaining gas gauge liquid s or freezes to ice. This creates an exhaust-free power plant, when one of the at the oxygen from air separated nitrogen apart. By the gas turbine<b>36</b> - please refer <b>Fig.</b> 1 - is out which the compressor <b>32</b> for air or air enriched with oxygen or for pure Oxygen - see <b>Fig.</b> 1 - driven.

The combustion chamber pressure vessel <b>1</b>, The first connecting line <b>2</b> and the heat exchanger pressure vessel <b>3</b> are so constructed that the pressure receiving wall outside lies. Inside the series followed by: insulation<b>7</b>, Consecutively connected channels <b>8th</b>. <b>9</b> and <b>10</b>In which flows pure gas and a thermally conductive, largely impermeable and refractory lining <b>21</b>, Only within this Ausklei manure <b>21</b> flowing raw gas.

LIST OF REFERENCE NUMBERS

<b>1</b>

Combustion chamber pressure vessel

<b>2</b>

connecting line

<b>3</b>

Heat exchanger pressure vessel

<b>4</b>

connecting line

<b>5</b>

Gas cleaning pressure vessel

<b>6</b>

connecting line

<b>7</b>

thermal insulation

<b>8th</b>

channel

<b>9</b>

channel

<b>10</b>

channel

<b>11</b>

Fuel and oxidant and Abgasrezirkulationseintritt

<b>12</b>

Rohgasaustritt

<b>13</b>

Clean gas outlet

<b>14</b>

Ash outlet connection

<b>15</b>

heat exchanger

<b>16</b>

Raw gas inlet

<b>17</b>

Rohgasaustritt

<b>18</b>

Raw gas inlet

<b>19</b>

Clean gas outlet

<b>20</b>

Flyash - (possibly with gypsum) outlet

<b>21</b>

inner heat conducting mostly gas-tight and fireproof lining (Wall) in

<b>1</b>

.

<b>2</b>

and

<b>3</b>

on the heat exchange between raw and Clean gas is effected

<b>22</b>

Heizflächenraum

<b>23</b>

Pure gas inlet

<b>24</b>

filter

<b>25</b>

obturator

<b>26</b>

Piece for Quenchgaszufuhr

<b>27</b>

combustion chamber

<b>28</b>

Stub for the additive supply (z. B. lime, ammonia)

<b>29</b>

obturator

<b>30</b>

Piece for Quenchgaszufuhr

<b>31</b>

Compressors for gas

<b>32</b>

Compressor for air or air enriched with oxygen or for pure oxygen

<b>33</b>

combustor

<b>34</b>

Heat exchanger (designed as a heat exchanger tank and Verbin nection line walls and - if necessary - heat exchanger)

<b>35</b>

gas cleaning

<b>36</b>

Gas turbine with generator

<b>37</b>

Heat recovery steam generator including steam turbine and generator

<b>38</b>

obturator