KR20110106362A - Extracting and cooling system for large flows of heavy ashes with efficiency increase - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates to a system for extracting and regenerating a large amount of energy for a large specific gravity ash produced by a solid fuel boiler, which is typically fixed by a boiler designer to a value of approximately 1.5% of total combustion air. The final temperature of the extracted ash can be reduced without increasing the air flow entering the. When the air flow required for cooling exceeds the maximum allowable in the boiler, the system will be directed to the air inlet duct that enters the air / smoke exchanger on the air side, thanks to the separation of the excess air and the possible steam from the cooling environment created by the ash itself. Can be.
The separation of the surroundings of the cooling system is automatically adjusted based on the ash temperature signal from the system to the discharge. If cooling air is not sufficient to cool the ash, the cooling efficiency can be further improved by dispensing water.

Description

EXTRACTING AND COOLING SYSTEM FOR LARGE FLOWS OF HEAVY ASHES WITH EFFICIENCY INCREASE}

The present invention relates to a plant and method for extracting, cooling and regenerating thermal energy for large flows of heavy ash made by solid fuel boilers.

Since solid fossil fuels are still needed to produce electrical energy, coal or lignite, which also has a high ash content, is used more frequently for combustion. Coal burning in high-power boilers often produce ash with a high specific gravity of up to 100 tonnes per hour, with a high percentage of unburned material. This amount of drying, or major dry cooling, requires as much as two or three times the flow of cooling air than fossil fuels with high heat-producing power.

As described in patent document EP 0471055 B1, in several known extraction and dry cooling of ash, the cooling air is once heated, from the bottom of the boiler into the boiler, while being affected by the heat exchange efficiency by the extraction and dry cooling. You are guided. Thus, the greater the amount of ash produced in principle, the more regeneration of the heat supplied to the boiler by the cooling air in the manner described above for heat exchange by air and combustion of unburned material.

However, to avoid adverse effects of combustion efficiency from being guided from the bottom into the combustion chamber rather than from burners or other specific air inflows and / or undesirable effects in the generation of NOx. To almost avoid, it is desirable for the boiler designer to limit this amount to a maximum of 1.5% of the total combustion air.

As is known, above all, if the ash as described above flows largely with a high content of unburned material at high temperatures, the known cooling system is associated with the drying of heavy ash or major dry cooling in an effective and efficient manner. Cooling air cannot be disposed of continuously. In particular, although the cooling system may be capable of cooling, thermal energy recovery and disposal as described above, the cooling system is equipped with a complex large plant which requires considerable operating and processing costs.

Patent document WO2008 / 023393, incorporated herein by reference, discloses that excess air can be sent to the smoke duct when the air flow required to cool the extracted specific gravity exceeds the maximum flow that can enter the combustion chamber. It is disclosed that this is due to the pressure separation of the cooling environment made by the ash itself. In patent document WO2008 / 023393, the position at which the excess air can be guided is the above-mentioned duct located upstream or downstream of the air / smoke exchanger.

A potential limitation of the system described in patent document WO2008 / 023393 is that the heat content associated with the cooling air used downstream of the pressure separation system is reduced, and all the flowing smoke that must be treated by the equipment located downstream of the air inlet is increased. Is the point.

Indeed, in the case of inhaling hot air downstream of the air / smoke exchanger, the heat content of the cooling air is reduced overall, and the total temperature in the flue smoke increases, apart from the increase in power absorbed by the equipment required for the smoke treatment. To change.

In the case where hot air is drawn into the smoke duct upstream of the exchanger, since the cooling air is at a lower temperature than the combustion smoke flow, the overall increase in the hot air flow + smoke flow entering the exchanger is the air / smoke heat of the surroundings of the device. It leads to deterioration of the exchange efficiency.

In particular, the temperature of the cooling air described above can reach approximately 200 ° C., thus, as described above, when cooling air is introduced into the smoke having a temperature of approximately 400 ° C., in practice the operating principle of the air / smoke exchanger On the basis of the present invention, which may result in an uneconomical balance in the air / smoke exchanger, and if the heat content of the flow entering the smoke increases, it is not desirable to be transferred to the air unless it is a negligible part.

Moreover, the hot air entering the smoke duct (upstream or downstream of the exchanger) has an electrostatic precipitator disposed downstream of the air / smoke exchanger than the design data, independent of the total increase in temperature of the smoke flow to be treated. To accommodate large total flows. This situation results in a deterioration of the efficiency of the electrostatic separator, caused by an increase in the speed of entry and, above all, by an increase in ash resistance.

Based on the above, the technical problem solved by the present invention is to provide an apparatus and method which can solve the above-described disadvantages with respect to the prior art.

This problem can be solved by the plant according to claim 1 and the method according to claim 22.

Preferred features of the invention are also shown in the dependent claims, which refer to the independent claims.

The present invention provides important advantages that can be seen overall in terms of the preferred embodiments described below.

The main advantage of the present invention is that the present invention can maximize the regeneration of sensible heat contained in excess cooling air used in the second plant portion downstream of the pressure insulator.

Indeed, the arrangement presented in the present invention allows the cooling air to enter the air flow of the environment sent to the air / smoke exchanger before entering the combustion chamber. Before entering the exchanger, the ambient air mixed with hot cooling air is used for its temperature rise and efficient preheating. This configuration makes the efficiency of the air / smoke heater hardly change and makes it possible to recover the sensible heat of the cooling air. Indeed, the present invention enables all regeneration of sensible heat obtained by cooling air in the plant portion downstream of the pressure separator and at the same time ensures that the temperature and smoke flow traversed by the electrostatic precipitator do not change, thereby improving the separation efficiency of the pressure separator. Do not lower.

The invention also enables the advantage of the system of patent document WO2008 / 023393, ie efficient drying of the ash or major dry cooling without exceeding the above-described limits of 1.5% for the cooling air guided from the bottom to the combustion chamber.

Substantially, the present invention optimizes the systems disclosed in Patent Documents EP 0471055 B1 and WO 2008/023393 by increasing the possibility of thermal regeneration when applied to large amounts of ash from lignite or coal having a high ash content. You can.

Combining the preferred embodiments described below, the present invention reduces the final temperature of the extracted ash without increasing the air flow entering the boiler flue, which is typically fixed by the boiler designer to a value of approximately 1.5% of the total combustion air. And air or dual air / water, extraction and cooling systems for large flows of high specific gravity ash made by solid fuel boilers. When the air flow required for cooling exceeds the maximum allowable amount of the boiler, the system will send excess air to the combustion air intake ducts, preferably to the secondary air ducts, thanks to the separation of the cooling environment preferably made by the ash itself. Can be.

Depending on the plant configuration and thus the concentrated or distributed load loss of the connecting line of cooling air, it is possible to advantageously provide a fan pressurized in the line, allowing right pressurization with the fluid.

The overall rise in the ambient air temperature entering the exchanger is negligible as the temperature difference (delta) between the smoke and the ambient air, which has a negligible effect on the overall performance of the air / smoke heater. .

The separation of the surroundings of the cooling system is automatically adjusted based on the signal of the ash flow and / or temperature when the ash is discharged from the system.

If cooling air is not sufficient to cool the ash, the cooling efficiency can be improved by adding sprayed water. Typically the added quantity is dosed based on the flow and ash temperature to ensure complete evaporation of the sprayed water to obtain dry ash on discharge, if necessary, suitable for pneumatically conveyed and compressed.

Based on the preferred configuration, the system presented and used in the present invention mainly consists of the components as described in 1 to 10 as described below:

1. a transition hopper between an extractor and a boiler of the type described in patent document EP 0 471 055 B1 as mentioned above;

2. the extractor described above;

3. ash mill;

4. Transition reservoir between the conveyor-cooler and the compactor, for example in the form of a hopper;

5. said conveyor-cooler being provided with a nozzle for spraying water and a suitable portion to ensure re-mixing action of ash on the conveyor itself;

6. If cyclone separators and regulating valves are installed to remove the fine ash contained in the cooling air flow, allow the ambient air to enter the air / smoke exchanger to remove the maximum excess cooling air allowed by the boiler. Ducts or pipes for the connection between the most suitable location of the system and the conveyor-cooler (preferably the area of the discharge casing of the conveyor-cooler);

7. Possible fans in the line with the pipes described above in the case of a line in which the concentrated or distributed load loss is in absolute value greater than the drop value at the cooling air intake position;

8. Discharge end devices (e.g., simple closure connections with valves, vibration extractors, or any transfer or storage closure devices) to prevent uncontrolled air from entering the system while allowing the discharge of ash;

9. connecting pipes or ducts for venting moist air to said pipes of item 6 described above, and

An unusual end condition (high flow and / or temperature) of the ash, in which an exhaust end device corresponding to the apparatus described in item 8 described above is installed, which enables to discharge ash from the system while preventing external air return. A re-water mixer, optionally operable to the discharge end device of item 8 described above, in the case of a system in which adequate cooling of the ash can not be ensured; And

10. Adjustment and control system to ensure the operation as described in the following description of the operation.

Various advantages, features and uses of the present invention will be apparent from the various preferred embodiments described below, which are merely illustrative and the present invention is not limited to these embodiments.

1 schematically shows a preferred embodiment of the plant of the invention in an operating mode providing connection of the air intake line of the environment to the air / smoke heater and the second plant part and pressure separation between the two cooling environments Shown;
2 is a schematic longitudinal cross-sectional view of a separation zone of two cooling environments of the plant of FIG. 1;
3 is a sectional view along the line AA of FIG. 2;
4 schematically shows the plant of FIG. 1 in a different mode of operation that does not provide said separation in two cooling environments;
FIG. 5 is a cross sectional view of a continuous double shaft mixer equipped with nozzles for cooling air of the plant of FIG. 1, according to line BB of FIG. 1;
FIG. 6 is a schematic illustration of the plant of FIG. 1 in an operating mode that still provides the step of sending hot ash to the mixer of FIG. 5.

Referring to the drawings described above, a plant for extracting and cooling combustion residues, according to a preferred embodiment of the invention and for example of the type used in thermo-electric plants of solid fossil fuels, is indicated by reference numeral 1. have. As can be better seen from the description below, the plant 1 is particularly suitable for adjusting the large flow of heavy ash, for example generated by the combustion of coal or lignite with a high ash content.

For a clearer understanding, the different components of the plant 1 are subjected to residues, such as extracted combustion residues from the bottom of the combustion chamber (or boiler) indicated by reference numeral 100, until the combustion residues are disposed of. It is described below with reference to the route.

Just below the combustion chamber 100, or better than the transition hopper 105 of the combustion chamber, the plant 1 provides a dry extractor 9 which mainly impinges on the first extraction and transfer unit, in particular steel having a large thermal resistance. do. The extractor 9 itself is of known type and is disclosed, for example, in patent document EP 0 252 967, incorporated herein by reference. The extractor 9 collects ash having a high specific gravity, which is precipitated downward in the combustion chamber 100 through the transition hopper 105 described above.

The extractor 9 has, on the side wall of the extractor casing, a plurality of holes for inlet of external cooling air, which holes are distributed in a substantially constant manner according to the embodiment of the extractor 9 itself and each of these holes is It is indicated by reference numeral 10. Flow inlet means may be provided at the inlet 10 or the inlet may be active or de-activated. The extractor 9 may further comprise an additional external cooling air inlet 19, which air inlet is also preferably adjusted by an automatic valve or equivalent flow control means and by means of the extractor 9 itself. Disposed substantially at the end.

Cooling air exits through the inlets 9 and 10 in the extractor 9 and flows back to the inlet under the influence of the drop in the combustion chamber 100. More specifically, air inflow is generated by the drop in the transition hopper 105 and a drop adjusted by the combustion chamber 100 control system (generally about 300 Pa-500 Pa below atmospheric pressure) occurs below the transition hopper. do.

Downstream of the extractor 9, ash is conveyed to the compactor 3, which crushes most of the coarse portion of the ash to increase the heat exchange surface and improve this heat exchange and thus cooling efficiency.

Downstream of the compactor 3 further external cooling air is introduced and indicated by reference numeral 17, in which case flow adjusting means can also be installed as described above. Also in this case, the air coming from the inlet 17 is supplied in countercurrent through the presser 3 itself and along the first extractor 9, under the influence of the drop in the combustion chamber 100. The cooling air is useful for cooling the device as well as ash.

As shown in more detail in FIGS. 2 and 3, downstream of the compactor 3, ash is conveyed to the second steel belt conveyor-cooler 6 by a hopper / reservoir 8. As described in more detail below, the plant configuration described under the determined conditions allows the hopper 8 to operate as a reservoir, thereby accumulating ash to disconnect the two atmospheres of the extractor 9 and the conveyor / cooler 6. Can be guaranteed. In particular, when accumulated as described above, the conveyor 6 ensures a separation between the surrounding environment of the extractor associated with the pressure velocity of the combustion chamber 100 and the surrounding environment of the conveyor / cooler associated with the different pressure velocity of the area to be communicated. By operating continuously under the material head, it works correctly with the second extractor.

The minimum level sensor and the maximum level sensor, indicated by reference numeral 7, and the floor leveler 18 are associated with the hopper 8 and are also disposed at the beginning of the conveyor 6 entry.

The position indication of the bed adjuster 18 associated with the velocity indication of the conveyor cooler 6 belt provides information on the re-volume flow, which is useful with the temperature indication to adjust the cooling fluid.

The ash on the conveyor 6 continues to be cooled by the air exiting from the outside through the additional inlet 11 arranged on the side wall of the extractor 6 itself from the outside in a similar manner as already described for the first extractor 9, And similarly the conveyor is provided with an additional outer cooling air inlet, designated by reference numeral 19, substantially disposed at the beginning of the conveyor 6 itself and preferably adjusted by an automatic valve or equivalent flow adjusting means. It can be provided.

If necessary, cooling on the conveyor 6 may be done with water finely supplied by the transfer nozzle 12 located inside the cover of the conveyor 6.

In this regard, it is noted that, among other things carried out by the air inlets 10, 11, 17 and 19 and the water transfer nozzle 12, the plant 1 can be equipped with a dual air-water cooling system. You will know.

The plant 1 further provides a means for replenishing the cooling air, heated after heat exchange by combustion residues, to the air exhaust duct 50 of the environment associated with the air / smoke exchanger 102. In an embodiment of the present invention, the replenishing means comprises a duct 51, the duct being heat-traced so that it is adequately insulated and condensate does not occur, and is arranged in accordance with an embodiment of the present invention. Optional adjustment by 150) (or equivalent), but may be stopped / started.

More specifically, the duct 51 is connected to the discharge area of the conveyor 6 (FIG. 1), preferably in the case of the mixer 2 (FIG. 6) the air intake area of the secondary surroundings. Connect with smoke exchanger. Thus, the duct 51 effluent upstream of the line is preferably associated with a secondary air fan 54 which sucks air from the environment into the air / smoke exchanger 102 (air side), the exchanger being combustion air. It is suitable for preheating and is typically provided in the combustion plant associated with the present invention. As is known, this suction zone has a negative pressure which is provided to the above described air fan 54 or by equivalent means for pressure control.

The type of exchanger 102 is typically so-called Ljungstrom.

The cyclone sorter 55 or equivalent device and the appropriate regulating valves 150, 59 for collecting the fine ash in the cooling air flow exiting the conveyor 6 and / or the mixer 2 are connected to the line of the duct 51. Can be connected.

A fan 56 is provided in the line with the duct 51 in which the concentrated or distributed load loss of the cooling air drops at the head upstream of the fan 54 or at the suction position on the head available at the fan. Greater than

In general, the intake duct of a combustion air fan that is sucked in from the environment and sent to the air / smoke exchanger is indicated at the optimal intake position of the cool air. As in FIG. 1, if the exchanger is of a three-branch type (the three-branch exchanger has two inlets 61 and 62 for combustion air (divided into primary and secondary), one for smoke Preferred position for introducing cooling air is detected as above by the intake duct of the secondary air. In practice, such a position is such that since the pressure level of the primary fan 58 is considerably greater than the pressure level of the secondary fan and thus the energy loss is greater when pumping, the fan of the primary air 58 In connection with the suction line is preferred.

In this case the plant configuration is not allowed to be connected to the intake line of the secondary air, but may be connected to the primary air line, which may, to a lesser extent, provide the advantages exhibited by thermal regeneration.

Intake of cooling air downstream of the (primary or secondary) fans 58, 54 also has the advantage that the fan always processes the same amount of intake air and thus the operating state is not changed.

In alternative embodiments, cooling air may be sent to enter the air side air / smoke exchanger 102 directly.

Cooling of the ash on the conveyor 6 can be done more effectively due to the presence of a substantially wedge-shaped member 14 which is fixed in relation to the particular re-mixing means, in particular with respect to the conveyor belt 6 itself, and the wedge-shaped member In this embodiment, it is formed as a share. The shared member 14 is distributed along the conveyor 6 in a substantially constant manner and arranged in the conveying section of the ash. As described above, the shared member 14 exposes the maximum surface usable for heat exchange with air and / or cooling water in this manner, allowing continuous re-mixing while being transported on the belt, thereby Plow.

Downstream of the conveyor 6, an automatic switching valve 16 (or means for selectively diverting the flow of ash) is provided to supply the cooled ash to the continuous mixer 2 or to the outflow means 13 towards the outside. Is optionally allowed and then communicated outwardly in this embodiment, which is shown in more detail in FIG.

Although not shown, the discharge conveyor 13 is provided with a device for controlling inlet air, which removes unexpectedly incoming air from the outside (or, in an embodiment, connects the system with several transport or storage closure surroundings). .

The mixer 2 with water allows for complete recooling if necessary to reach the temperature value while wetting or downstream ashing to reduce powder discharge under certain transport and disposal conditions. The mixer 2 is provided with a discharge casing 21 and at the same time a means capable of allowing re-ejection from the system by preventing uncontrolled external air return. Such a device may, for example, consist of a double clapet valve or rubber board and, when deformed under the influence of the weight of the ash, permits the discharge of ash to the minimum passage section required.

Based on the preferred embodiment, the pipe 66 connecting the mixer 2 with the duct 51 is provided with a valve 59 or an aeration of air and steam into the pipe with the corresponding means in the line. Is provided for.

The plant 1 comprises a temperature sensor and / or a volumetric sensor and / or a ponderal flow sensor of the ash, which in the present embodiment are at the outlet or end of the conveyor 6 and / or at the main extractor ( 9) or more preferably in the ash discharge section of the conveyor 13. Advantageously, a sensor of the type described above is also provided in the hopper / depot 8.

Subsequently in the hopper 8, a load cell or equivalent means may be provided to control the level of ash in the hopper / store.

Furthermore, temperature sensor means may be provided disposed in the duct 51.

The plant 1 comprises a control system which is suitable for controlling the operating mode of the plant 1 in relation to the amount of ash and the temperature, and in communication with the sensor means.

The operating mode of the cooling system which can be controlled by the plant 1 and in particular by the control means described above is shown in more detail here.

First of all, the re-temperature and / or flow values provided by the sensor means are compared with the predetermined and stored values by the control system, and on the basis of these comparison results, the operating mode most suitable for the operation of the plant 1 is determined. . With respect to temperature and / or flow measurement needs, it can be seen that the temperature rise of the ash is typically associated with an increase in flow in the plant 1 contemplated herein.

The plant in the starting phase is configured in the mode shown in FIG. 4 by adjusting all air inlet valves 10, 11, 17 and 19 and closing the automatic valve 150, corresponding to 1.5% of the combustion air. The total amount of air can exit the hopper 105 of the boiler 100 via bottom communication by traversing the ash in the extractor 9 and the conveyor 6 countercurrently.

This mode of operation is carried out until the ash temperature upon evacuation of the conveyor 6 reaches a predetermined value T _minimum ,

In this mode of operation, the control means have a belt of the extractor 9 so that the conveyor 6 has a greater flow of potential ash than the extractor 9 to substantially avoid the formation of material heads in the hopper 8. And the associated speed of the belt of the conveyor 6.

When the value exceeds T _minimum , the system operates to reduce and adjust the speed of the conveyor 6 in particular to accumulate ash in the hopper 8 and thus prevent the continuous ash, and the system also extracts the extractor. The valve 150 of the duct 51 is opened to create two different atmospheres, respectively, at the 9 and the conveyor 6, the first of which is related to the pressure in the boiler and the second is the surroundings. Is associated with the pressure in the air supply duct 51.

In this mode of operation, the air inlet valves 10, 19 and 17 of the extractor 9 and the hopper 8 are automatically adjusted so that only a total of 1.5% of the cooling air is concentrated in the extractor, the cooling air then being fed to the boiler and It can be introduced in the case of the nozzle 12 of the conveyor 6 by adding to the valve 11 the first air and water which performs the desired cooling, if necessary, up to the calculated percentage so as not to affect the operation of the air / smoke exchanger downstream. have. In this regard, in order to select a position to intake cooling air, the fan 54 always has the same amount of air, and when the cooling air through the duct 51 is increased, air drawn from the environment will be reduced. Able to know.

In this ambient separation configuration, the cooling air guided by the inlets 10, 17 and 19 and acting on the main extractor 9 traverses this countercurrent extractor and enters the combustion chamber 100 with a limit of 1.5%. Inlet 11 and, if located on conveyor 6, more than 1.5% of cooling air rises outwards through an inlet 19 corresponding to the inlet, which cools the conveyor to constant current. Suction through the duct 51, with steam made by local cooling of the water possible, by the drop caused by the support fan 56 and the air fan 54 located in line with respect to the duct 51. do.

In this way the maximum possible combustion of the possible unburned material on the extractor 9 belt is possible by minimizing the cooling water adjustment by the maximum cooling on the belt of the conveyor 6 and the associated energy returned to the boiler.

This mode of operation is illustrated by way of example in FIG. 1.

If the ash head described above is present, the load hopper 8 is prevented from emptying by controlling the speed of the conveyor 6 in accordance with the detection of the maximum and minimum level sensors 7. In particular, if the level reaches the minimum level, the speed decreases until it stops the conveyor 6, while when the minimum level is exceeded, the speed and thus the conveyor when the conveyor 6 is restarted and the maximum level is reached (6) the flow of the belt increases.

In the arrangement contemplated in the present invention, the control means have available additional information detected by the particular sensor means, in particular with respect to the temperature of the ash of the hopper 8 and the forward speed of the conveyor 6. Together with the (fixed) value of the extract, the above characterizes the re-volume flow accurately. In order to avoid possible blockage in the extraction section itself, it is specified that the extraction level must be greater than the appropriate margin in the size of the ash exiting the compactor 3.

Furthermore, in the additional mode of operation shown in FIG. 6, the plant 1 is also in the case of a very large (high) ash flow / temperature-even when the design value is exceeded-for example depending on the fuel type or the combustion chamber ( 100) can be adjusted by operation for cleaning. The temperature of the ash is the value (T _very In the case that the more important consideration than _high), the plant (1) provides a mode of operation as described at the end, and the conveyor 13 by the material of the high temperature in the change-over valve 16, instead of discharging the mixture (2) do.

In the mixer 2, an additional quantity is guided to provide the end temperature (typically approximately 80 ° C.) with the appropriate moisture content (preferably approximately 10%) to ensure that no powder is produced in the next transfer operation. ) Can be transferred.

In order to avoid the steam generated by the cooling as described above in the mixer 2 going back to the conveyor 6 (with the risk of condensation), the inverted "Y" shaped connection is conveyed to the conveyor 6. It can be provided directly between the mixer 2 and the duct 51. Because of this so-called construction, air and in this case steam arriving from the conveyor-cooler 6 communicate with the steam generated in the mixer 2 and proceed towards the smoke line connection duct. There is still a risk of condensation in these connecting ducts (between the mixer 2 and the main duct 51) where the design conditions can be adequately heated in view of the risk of condensate formation and associated ash deposition.

It will be appreciated that the predetermined value of the temperature and / or flow or amount of the given combustion air can be optionally set by the adjuster adjusting the plant 1.

It will further be appreciated that the mode of operation as described above includes only one of the various adjustment possibilities of the plant 1. A simpler mode of operation is provided, for example made when the ash head reaches a predetermined temperature value, and adjustment can be made to the remainder by appropriately adjusting the cooling air and water flow if necessary.

A series of operating modes as considered so far can be set manually or automatically by means of an adjustment and control system, which is adapted to discharge sprayed water when the air flow enters the extractor 9 and the conveyor 6. When feeding and when operating the switching valve, the ashing mode of the ash itself is determined to act on the formation of the separation zone, based on the ash temperature / flow value.

In general, the plant 1 has the ability to substantially adjust all operational variability and thus the flow of any ash, and in this respect there are no problems associated with the introduction of excess cooling air from the bottom of the boiler 100. You can see that. As described above, this diversity is obtained by inducing even a very large cooling air flow and by adding additional air flow, which additional air, if necessary, may be added to the air inlet duct of the surrounding environment, possibly with the addition of cooling water. Not suitable for induction in smoke exchanger.

In view of the above, it is preferred that the plant 1 is supplied via a control means of the plant in an appropriately used quantity so that it can all be vaporized during the cooling process and substantially at the outlet side of the conveyor 6. The dry ash is obtained and suitable for being automatically pressed and conveyed. This configuration can be obtained by maintaining the ash end temperature at 100 ° C or higher. The flow of water to be sprayed and sprayed, on the one hand, the heat to be removed from the ash (generated by the induction of the specific enthalpy change required between the temperature in the hopper 8 and the discharge end temperature), and on the other hand the enthalpy caused to the cooling air It will be controlled by the thermal equilibrium caused to equal the sum of the change in and the heat of evaporation of water.

In addition, sending part of the cooling air in the ambient air inlet duct to the air / smoke exchanger allows for maximum heat recovery associated with the cooling air, which is why the dry extractor described in the patent document EP 0 471 055 B1 used herein and It will be appreciated that there may be an associated performance advantage.

It will also be appreciated that the temperature of the ash can be made constant if there is a possibility of selectively acting cooling of the water by the nozzle 12 and there is a shared member or equivalent means.

Furthermore, apart from allowing more complete control of the plant parameters, it can be seen that the temperature sensor placed in the duct 51 can also identify the location of possible condensate formation in all the ducts 51 due to the steam resulting from the coolant. There will be. Indeed, knowing the temperature of the air itself and the quantity of atomized water makes it easy to calculate the relative humidity of the cooling air and confirms the following:

On either side, the moisture itself is not more than 100% by means of a margin adequately indicated;

On the other side, even in the possible cooling position of the path (and mainly on the cover of the conveyor 6 and on the surface of the connecting duct 51), the water content of the air does not allow condensation to be produced, which is a system operation. Can cause problems.

In order to avoid any risk of molded condensate in the system, additional connecting ducts (or equivalent means) may be used to selectively move the outside air inlet over these ducts and the flow of hot air reaching from the transition hopper 105. By providing a valve to regulate the flow of air in the cold environment, it can be provided between the transition hopper 105 and the conveyor 6 near the hopper 8. This configuration can raise the air temperature in the system to the level to eliminate the risk of condensate formation. The above described adjustment of the inhaling hot and cold air flow can be generated based on the detection of the above described temperature sensor located in the duct 51.

Finally, the above described separation of the two surroundings is configured such that it can be obtained by a device different from the above described device. For example, an additional device may be provided between the extractor 9 and the conveyor 6 as a clappet valve or equivalent device, and furthermore, separation of the two surroundings may result in variable flow associated with the compactor 3. A second milling step by means of hopper / reservoir 8 can be applied to produce the necessary ash head in the hopper suitable for isolating the surrounding environment.

The present invention allows efficient energy recovery induced by sending the maximum outer air flow to the extractor 9 and significantly reduces the amount of air in the second extractor 6 (for the addition of water) and hence the energy required to treat the smoke. It will be appreciated that it can be reduced.

The object of the invention also relates to a method for extracting, cooling and regenerating the energy of a high specific gravity as described in connection with the plant 1.

The invention has been described with reference to preferred embodiments. It will be appreciated that several embodiments fall within the scope of the present invention.

Claims (41)

In energy-generating plants, for example, a plant which extracts and cools heavy ashes by means of thermal energy regeneration of a type suitable for use in conjunction with combustion chambers, for large flows of particularly heavy ashes from solid fossil fuels. 1),
(a) extracting and conveying means (9, 6) for extracting and conveying ash having a high specific gravity from the combustion chamber (100);
(b) disposed in the extraction and conveying means 9 and 6, with at least a portion of the cooling air generally disposed so as to be guided from the lower part of the combustion chamber into the combustion chamber 100, and the extraction and conveying means A cooling system (10, 11, 19, 17, 12) for determining the supply of the cooling air to and cooling the ash with a high specific gravity;
(c) an air / smoke exchanger 102 by means of an air inlet duct 50; 57 and a first ambient of the extraction and transfer means 9, 6, associated with the atmosphere of the combustion chamber 100; Pressure insulating means (8) for determining an atmosphere separation of a second surrounding of said extracting and conveying means (9, 6), which can be connected to an air inlet of said air / smoke exchanger;
(d) means (51) for partially replenishing the cooling air to an air inlet duct (50; 57) to the air / smoke exchanger (102) or to an inlet of the air / smoke exchanger; And
(e) a plant (1) for extracting and cooling heavy ashes, characterized in that it comprises control means for determining the action of the pressure adiabatic action of the surrounding environment according to the ash temperature and / or flow. The method according to claim 1,
The cooling system 10, 11, 17, 19, 12 takes a dual air-water type, and the control means determines the cooling action of the water according to the temperature and / or flow of the heavy ash. Plant (1) for extracting and cooling this large ash. The method according to claim 1 or 2,
The overall arrangement is that the cooling system (10, 11, 17, 19, 12) in the pressure separation state of the first and second surroundings of the ash having a high specific gravity of the cooling air in the first surroundings A plant (1) for extracting and cooling heavy ashes, characterized in that it is supplied to flow and backflow and is determined to supply cooling air to the flow and rectification of the heavy ashes in the second surrounding environment. The method according to claim 1 or 2,
The control means comprise a heavy gravity ash, characterized in that it comprises a temperature and / or flow sensor of the heavy gravity ash, arranged in the extraction and conveying means 9, 6, 13 and / or in the pressure adiabatic region 8. Extraction and cooling plant (1). The method of claim 4,
A plant (1) for extracting and cooling heavy ashes, characterized in that a sensor of temperature and / or flow of the heavy ashes is arranged in the end region of the extraction and conveying means (6, 13). The method according to claim 5,
The plant (1) for extracting and cooling heavy ashes, characterized in that the temperature and / or flow sensors are arranged at the outlet of the heavy ashes. The method according to claim 1 or 2,
The plant (1) for extracting and cooling heavy ashes, characterized in that the control means comprise a load sensor arranged in the pressure insulating zone (8). The method according to claim 1 or 2,
The control means determines the separation of the first and second surroundings such that the cooling air flow entering the combustion chamber 100 from below does not exceed a predetermined amount of total combustion air, preferably approximately 1.0% -1.5%. A plant (1) for extracting and cooling ash having a high specific gravity. The method according to claim 1 or 2,
The means for replenishing (51) is a plant (1) for extracting and cooling heavy ashes, characterized in that the air inlet ducts (50; 67) are in communication with the second ambient, substantially under the cooling process. . The method according to claim 1 or 2,
The replenishing means 51 effluent is conveyed to the air inlet ducts 50 and 57 upstream of the fans 54 and 58 to increase the air head. (One). The method according to claim 10,
The replenishing means (51) is a plant (1) for extracting and cooling heavy ashes, characterized in that the effluent is conveyed to the air inlet duct (10) upstream of the secondary air fan (54). The method according to claim 1 or 2,
It is disposed in the replenishment means 51, and includes a means 150 for adjusting the flow of air from the replenishing means 51 to the air inlet duct (50; 57) Plant (1) for extracting and cooling ash. The method according to claim 1 or 2,
The pressure insulation means comprises a means 150 which is controlled by the control means to determine the first and second ambient separations if necessary, and means 150 for stopping / actuating the replenishment means. Plant for extracting and cooling large ashes (1). The method according to claim 1 or 2,
The plant (1) for extracting and cooling heavy ashes, characterized in that the control means comprise at least one temperature sensor arranged in the replenishment means (51). The method according to claim 1 or 2,
The extraction and conveying means comprise a first extraction unit 9 suitable for being arranged or arranged directly below the combustion chamber 100 and a second conveying unit 6 arranged downstream of the first extraction unit 9 and The plant (1) for extracting and cooling heavy ashes, characterized in that the pressure insulating means (8) make a pressure separation between the first extraction and transfer units (9, 6). The method according to claim 14,
The plant (1) for extracting and cooling heavy ashes, characterized in that the control means controls the speed of one or more of the extraction and transfer units (9, 6). The method according to claim 1 or 2,
The pressure insulated means 8 comprises means for making a head of a heavy material between the two surroundings so as to determine the pressure separation of the two surroundings. Cooling plant (1). 18. The method of claim 17,
The plant (1) for extracting and cooling heavy ashes, characterized in that the pressure insulating means comprise storage means (8) suitable for receiving the heavy ashes which make up the head. The method according to claim 18,
The plant (1) for extracting and cooling heavy ashes, characterized in that the pressure insulation means comprises a hopper (8) suitable for receiving the heavy ashes that make up the head. 18. The method of claim 17,
The plant (1) for extracting and cooling heavy ashes, characterized in that the control means comprise at least one level sensor (7) arranged in the head. The method according to claim 1 or 2,
Means for supplying cooling air and possible steam from the mixing means 2 to the replenishing means 51 from the mixing means 2 and the specific gravity ash disposed in the discharge portion of the ash and completing the cooling process of the ash. Plant (1) for extracting and cooling the high specific gravity ash comprising a. As a method of extracting and cooling heavy ash from the combustion chamber for large flows of particularly heavy ash from eg fossil fuels in energy-generating plants,
(a) extracting ash having a high specific gravity from the combustion chambers 100 and 105;
(b) replenish the cooling air along the extraction and conveying paths 9, 6, 13, which guides at least a portion of the air from the lower part of the combustion chambers 100, 105 to the combustion chamber, downstream of the cooling process; Thereby cooling the high specific gravity ash along the extraction and transport paths (9, 6, 13);
(c) selectively acting pressure adiabatic between the first and second surroundings disposed along the extraction and transfer path in accordance with the temperature and / or flow of the heavy ash;
(d) replenishing the air inlet duct (50; 57) or the air inlet of the air / smoke exchanger (102) according to the temperature and / or flow of the high specific gravity ash,
The first environment is located directly below the combustion chambers 100 and 105 and the second environment is located below the first environment and the air inlet ducts 50 and 57 of the air / smoke exchanger 102 Or a method for extracting and cooling a heavy ash, characterized in that it is connected to the air inlet. The method according to claim 22,
Wherein step (b) is of dual air-water type and provides a cooling action of the water according to the temperature and / or amount of the specific gravity ash. The method according to claim 22 or 23,
The step (b) is a method of extracting and cooling the ash with a high specific gravity, characterized in that to provide a cooling action of the water in the second environment. The method according to claim 22 or 23,
In the step (b), under the pressure separation between the first and second surroundings, the cooling air in the first surroundings is flowed and rectified by ash having a high specific gravity, and the cooling air is concentrated in the second surroundings. A method for extracting and cooling heavy ashes, characterized by providing a step of reflowing with large ash flows and countercurrents. The method according to claim 22 or 23,
Detecting the temperature and / or flow of the heavy gravity ash carried out in the extraction and conveying paths 9, 6, 13 and / or the pressure adiabatic zone 8. And how to cool. 27. The method of claim 26,
A method for extracting and cooling heavy ashes, characterized in that the temperature and / or flow detection of the heavy ashes is carried out in the end zone of the extraction and conveying path (6, 13). The method of claim 27,
Wherein said temperature and / or flow detection is carried out upon evacuation of the high specific gravity ash. The method according to claim 22 or 23,
A method for extracting and cooling heavy ashes, characterized by providing a load detection step carried out in the pressure adiabatic zone (8). The method according to claim 22 or 23,
The step (c) is such that the separation of the surrounding environment is such that the cooling air-flow that cools the air entering the combustion chamber 100 from below does not exceed a predetermined amount of the total combustion air, preferably approximately 1.0% -1.5%. A method for extracting and cooling heavy ash, characterized by providing a step that is performed. The method according to claim 22 or 23,
The replenishment of the air / smoke exchanger 102 to the air inlet duct 50 originates from the second ambient environment and occurs substantially downstream of the cooling process. . The method according to claim 22 or 23,
Replenishment from the air / smoke exchanger 102 to the air inlet ducts 50 and 57 provides effluent in the ducts 50 and 57 upstream of the fans 54 and 58 to increase the air head. Method of extracting and cooling ash with a large specific gravity. The method according to claim 32,
The replenishment from the air / smoke exchanger 102 to the air inlet duct 50 provides a effluent to the duct 50 upstream of the secondary air fan 54 to extract heavy ashes. And how to cool. The method according to claim 22 or 23,
Adjusting the flow of air to the air inlet duct (50; 57) or to the air inlet of the air / smoke exchanger (102). The method according to claim 22 or 23,
The step (c) provides that the pressure adiabatic is obtained by stopping / activating the supply of cooling air to the air inlet ducts 50 and 57 or to the air inlet of the air / smoke exchanger 102. Characterized by the method for extracting and cooling a heavy ash. The method according to claim 22 or 23,
Provide a temperature detection step performed in the air inlet ducts 50, 57 of the air / smoke exchanger 102 or in the means 51 for supplying the air inlet. How to extract and cool. The method according to claim 22 or 23,
The extraction and transfer path includes a first extraction portion disposed directly below the combustion chamber 100 and a second transfer portion disposed below the first portion, wherein step (c) includes the pressure insulation to extract the portion. And between said conveying part and a method for extracting and cooling ash having a high specific gravity. 37. The method of claim 36,
The step (c) is characterized in that the step of controlling the extraction and / or the feed rate of the ash along the path method for extracting and cooling the heavy ash. The method according to claim 22 or 23,
And step (c) provides a step of forming a head of high specific gravity ash between the two surroundings to determine the pressure separation. 42. The method of claim 39,
Step (c) provides for detecting the level of the head. The method according to claim 22 or 23,
Providing a mixing step of the high specific gravity ash and suitable for completing the cooling process of the high specific gravity ash, and used or generated by the mixing step in the air inlet duct 50; 57. A method for extracting and cooling heavy ashes comprising providing refrigeration of cooling air and possible steam.

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