KR100563962B1 - Heat exchanger for exhaust gas heat recovery - Google Patents

Abstract

The present invention relates to a waste heat recovery apparatus that effectively recovers waste heat of exhaust gas (exhaust gas), and more specifically, to pressure loss or mixing of solid particles and exhaust gas injected into waste heat recovery apparatus (heat exchanger). A waste heat recovery device of improved construction which allows mixing without pressure imbalance.

The waste heat recovery apparatus of the present invention includes a riser tube in which preheat gas and solid particles are mixed and flowed; A separation plate installed above the riser and separating the solid particles from the mixed airflow of the solid particles and the exhaust gas discharged from the riser; (C) upper and lower flanges fixed to the upper and lower outer surfaces of the riser and having at least one hole formed on the surface thereof; 입자 a solid particle recovery pipe connected to the upper and lower ends of the flange; And an outer tube to which the flange is coupled to the upper and lower portions, respectively, and a fluid inlet and a fluid discharge port are formed at one side of the surface, and a mixing hole is formed at the lower portion of the mixing space of the exhaust gas and the solid particles. It includes.

According to the configuration as described above, the pressure loss does not occur when mixing the exhaust gas and the solid particles do not need to increase the air volume, and thus the blowing means for pressurizing the exhaust gas can be miniaturized. In addition, since the waste heat of the exhaust gas is recovered twice in each of the riser and the solid particle recovery tube, the heat recovery rate is higher than that of the conventional waste heat recovery apparatus (heat exchanger). In addition, by adopting the double valve system, it is possible to more effectively suppress the adhesion of dust lumps due to the disturbance and condensation of the flow (mixed air stream) due to solid particle injection.

Waste heat recovery device, solid particle, double valve, mixing space, pressure loss, solid particle recovery pipe, riser pipe, vertical pipe, solid particle injection system, control system, long-term operation, condensation prevention, preheating

Description

Waste heat recovery system {HEAT EXCHANGER FOR EXHAUST GAS HEAT RECOVERY}             

1 is a plan view showing a waste heat recovery apparatus according to an embodiment of the present invention.

2 is a cross-sectional view taken along the line A-A of FIG.

Figure 3 is an exploded perspective view showing a multi-tubular waste heat recovery apparatus according to another embodiment of the present invention.

Figure 4 is a schematic block diagram showing a multi-tubular waste heat recovery apparatus according to another embodiment of the present invention.

5 is a cross-sectional view taken along line B-B in FIG. 4.

Figure 6 shows the upper structure of the riser shown in FIG.

7 is a block diagram showing an operation process of the waste heat recovery apparatus shown in FIG.

Figure 8 shows a multi-tubular waste heat recovery apparatus according to another embodiment of the present invention, showing in more detail the internal structure of the heat transfer unit and the separation unit installed on top of the heat transfer unit not shown in FIG.

Figure 9 is a perspective view of the inside of the exhaust gas inlet portion according to an embodiment of the present invention.

10 shows a particle injection portion and a particle preheating portion employing a double valve according to an embodiment of the present invention.

[Description of Drawing Reference]

10 ... waste heat recovery device, 20 ... mixing part,

30 ... heating section, 40 ... separation section,

50 exhaust gas inlet, 60 exhaust gas outlet,

310 ... rise tube, 320 ... solid particle collection tube,

410 separator, 510 exhaust gas inlet,

520, 521, 522 valves, 530 blowers,

700 ... flange, 800 ... diffuser.

The present invention relates to a waste heat recovery apparatus for recovering heat energy (waste heat) of exhaust gas (exhaust gas) discharged from an incineration plant or urinary tract of industrial waste, and more specifically, a separate cleaning operation for a heat transfer surface is performed. It is considered to be simpler than the conventional waste heat recovery device and is impossible to recover in the past because it is not necessary, and therefore, the operation efficiency is better than that of the conventional waste heat recovery device, and it does not require dust removal means such as a soot blower. The present invention relates to a waste heat recovery apparatus of a novel configuration designed to recover waste heat even in a flue gas having a temperature lower than 300 ° C.

In addition, the present invention relates to a waste heat recovery apparatus of an improved structure that can ensure stable operation in a wider operating range (particle circulation amount) than in the prior art.

The temperature of the flue gas discharged from various incinerators, industrial furnaces, etc. is usually high, about 500 to 600 ° C. In the past, no technology has been developed to recover waste heat from such hot flue gas. .

Then, various types of waste heat recovery devices, such as waste heat boilers, have been developed since about 20 years ago, and the heat energy of waste gas, which has been dumped for a while, is used for heating and hot water supply.

The conventional waste heat recovery apparatus is divided into a vertical type or a horizontal type according to the arrangement direction of the heat transfer pipe and the direction of the movement path of the exhaust gas, and is divided into a single type and a multi type according to the number of heat transfer tubes through which the exhaust gas passes.

In general, the exhaust gas discharged from industrial furnaces or incinerators contains a considerable amount of dust, and when hot exhaust gas is brought into contact with a relatively low heat transfer surface when it is passed through a waste heat recovery system without removing dust. Water droplets (condensation) and the dust are entangled, resulting in a lump of dust adhering to the heat transfer surface. This phenomenon is called “fouling” and this adhesion (deposition) has occurred very frequently, especially in the waste heat recovery apparatus of the conventional configuration adopting the shell & tube type. Therefore, if the heat transfer surface is contaminated or further corroded by the mechanism, the total amount of heat energy (heat transfer amount) recovered by the waste heat recovery device is reduced, and thus periodic cleaning is required.

Conventionally, in order to prevent such "fouling" phenomenon, the fine solid particles are added to the exhaust gas passing through the waste heat recovery device (heat exchanger), so that the solid particles are heated when the solid particles flow inside the heat exchanger tube, and thus the inner surface of the heat exchanger tube is heated. A descaling method was used to allow the dust mass adhering to the powder to fall off by price or to scrap the dust mass little by little when the solid particles rubbed the dust mass. The method of blowing using a blower was used.

The heat exchanger (waste heat recovery device) described in Patent No. 242226 is applied with the above-described method of removing the solid particles, and the heat exchanger includes (1) separating heat transfer pipes through which a cooling fluid flows and (2) solid particles located above the heat transfer tubes. It consists of a part and a solid particle distribution chamber located at the lower part of the heat transfer pipe, a plurality of ascending pipes connecting one of the separation part and the distribution chamber, and one downcomer (solid-solid recovery tube), and ⑤ exhaust gas inlet and outlet. According to the publication described in the patent, the heat exchange device is a solid particle located in the distribution chamber by the pressure of the exhaust gas supplied from the exhaust gas inlet is moved to the top along a plurality of risers and thus the solid particles moved to the upper The waste heat is recovered by the circulation collected in the distribution chamber again along the downcoming pipe so that the dust mass is removed. A distribution plate having a plurality of through holes is installed at the lower portion of the distribution chamber, so that the exhaust gas flowing into the distribution chamber is discharged through the through hole. To float the solid particles on the distribution plate.

According to this configuration, the flow of the exhaust gas passing through the through-holes in the process of changing the jet-flow separation of the flow occurs around the through-holes resulting in a vibration of the pressure, a high-power blower fan in order to remove the vibration of the pressure There is a problem to increase the supply pressure of the exhaust gas using. In addition, even if the supply pressure of the exhaust gas is increased by a high-power blower, some of the riser may cause the solid particles to fall. Such abnormal operating characteristics appear as the usage (or flow amount) of the solid particles increases. Therefore, it is necessary to secure an operating region capable of operating stably even if the flow rate range of the solid particles is widened for the practical use of the waste heat recovery device.

The present invention has been made to improve such a conventional problem, and forms a mixing space in the lower portion of the heat exchanger (waste heat recovery device), and communicates the riser pipe through which the exhaust gas is moved and the solid particle recovery pipe through which the solid particles are moved. By doing so, it is an object to provide a waste heat recovery apparatus that minimizes the pressure loss of the exhaust gas (exhaust gas) by allowing the solid particles and the exhaust gas to be mixed without a distribution plate. In other words, in the present invention, the inlet flow conditions (exhaust gas) is introduced to the inside of the ascension pipe in the process of flowing in the inlet flow condition to provide a stable inlet flow condition, the solid particles in a position that can form a smooth flow The mixing was to minimize the pressure imbalance and pressure loss caused by the mixing of the solid particles.

In order to minimize such pressure loss and instability (pressure fluctuation) of the exhaust gas, the present inventors install a mixing space in which the ascending pipe and the solid particle recovery pipe communicate at the same time in the waste heat recovery device, and the heat transfer part of the waste heat recovery device. The flow path of the solid particles is installed in an annular shape between the vertical pipes extending downwards so that the solid particles and the exhaust gas are easily mixed and heated, thereby improving the heat transfer performance, that is, the heat recovery rate. The losses have been drastically reduced.

In addition, the present invention by forming a bent pipe (solid particle recovery tube) in which the solid particles for dust removal are recovered, the solid particles heated by contact with the exhaust gas during the flow along the riser tube to the solid particle recovery tube Another purpose is to provide a waste heat recovery apparatus that allows the waste heat of the solid particles to be recovered secondarily when descending.

In addition, in the present invention, in employing a plurality of units in which the riser and the downcomer (solid particle recovery tube) are modularized in the waste heat recovery system, the present invention can solve the problem of pressure imbalance in the riser, which is a problem of the prior art. In order to stabilize the flow field by installing an annular particle passage in the middle of the straight pipe, and to cope with such pressure imbalance, the bell mouth is used as the bell inlet of the lower inlet through which the flue gas flows, and the area of the section where the particle passage is installed has a smooth curvature. It is another object to provide a waste heat recovery apparatus that can be reduced to ensure a stable operability in a wider operating area (particle circulation amount) than conventional.

In addition, in the present invention, the lower space of the riser acts as a kind of plenum chamber to recover the static pressure and reduce the flow rate of the flue gas so that even flow conditions can be formed when the flue gas passes through the vertical tube. Another object of the present invention is to provide a waste heat recovery apparatus in which an inlet guide tube in the form of a perforated plate is introduced to the bottom thereof.

In addition, the present invention by installing a double valve in the replenishment line of the solid particles, waste heat recovery device to prevent the disturbance and condensation phenomenon of the flow field (circulating fluidized bed) when the solid particles are injected through the valves in sequence There is another purpose to provide.

It is another object of the present invention to provide a waste heat recovery apparatus having an improved structure in which external leakage of solid particles can be actively prevented.

Another object of the present invention is to provide an automated waste heat recovery apparatus in which the discharge of condensed water, injection / discharge of solid particles, cleaning, operation mode selection, and the like can be made by a simple button operation.

Waste heat recovery apparatus of the present invention for achieving the above technical problem, the rising pipe is mixed and flows the gas and solid particles; A separation plate installed above the riser and separating the solid particles from the mixed airflow of the solid particles and the exhaust gas discharged from the riser; (C) upper and lower flanges fixed to the upper and lower outer surfaces of the riser and having at least one hole formed on the surface thereof; 입자 a solid particle recovery pipe connected to the upper and lower ends of the flange; And an outer tube to which the flange is coupled to the upper and lower portions, respectively, and a fluid inlet and a fluid discharge port are formed at one side of the surface, and a mixing part is formed at the lower part of the mixing space of the exhaust gas and the solid particles. It includes.

In addition, the waste heat recovery apparatus of the present invention is a heat transfer unit for the waste heat of the exhaust gas is delivered to the circulating water; A mixing unit installed below the heat transfer unit to be introduced into the heat transfer unit in a state in which the exhaust gas and the solid particles are mixed; A separation unit installed above the heat transfer unit so that the exhaust gas discharged from the heat transfer unit and the solid particles are separated from each other; And a replenishment line of solid particles in communication with the separator with a double valve. It may be configured to include, in addition to the automatic control system for determining the opening and closing time of the valve can be installed. At this time, the heat transfer unit may be a form of a plurality of built-in waste heat recovery unit consisting of the riser and the solid particle recovery tube.

The "solid particles" is to remove the dust mass adhering to the inner surface (inner wall) of the riser, and is preferably an inorganic ceramic material such as ceramic powder, glass powder, cement, limestone, etc., and introduced into the waste heat recovery apparatus of the present invention. It is preferable that it is the size which can be raised by the flue gas which becomes.

The "fluid" is for recovering waste heat from the riser and the solid particle recovery tube through which the exhaust gas and the solid particles are moved, liquid or gas such as water having high thermal conductivity may be used.

The riser is a tube that passes when the exhaust gas flowing into the bottom of the waste heat recovery apparatus flows upward, and may be formed of one tube or a plurality of tubes for widening the heat transfer surface area. At this time, the solid particles moving upward with the exhaust gas through the riser are heated by receiving heat from the exhaust gas during the movement.

The separation plate installed above the riser is for separating the solid particles mixed with the flue gas from the mixed air stream (exhaust gas + solid particles), and prevents the progress of the solid particles supported by the flue gas to lose its flotation force. The solid particles are separated from the mixed stream.

The solid particle collection tube is to move the solid particles accumulated in the upper portion of the riser by the separation action of the separator plate to the lower side mixing portion of the riser, and may be formed as a single tube, but the circulation of the solid particles is smooth. To this end, and in the solid particle recovery tube, it is preferable to form a plurality of tubes so that the waste heat recovery can be sufficiently made. Particularly, when the solid particle recovery tube is formed in a spiral shape surrounding the riser, the moving distance of the solid particles moving to the mixing part along the solid particle recovery tube is long, so that the waste stays longer. It can be recovered.

The outer tube includes: ① a heat transfer unit in which the solid particle recovery pipe and the riser are built; A separation unit located above the heat transfer unit in a form including a separation plate; And a mixing unit formed at a lower portion of the heat transfer unit.

① The heat transfer part is a tube through which fluid flows, and may form a space enclosed therein by using a plate or a diaphragm (bulb) having flanges on the top and bottom surfaces thereof, and a fluid discharge port used for supplying and discharging fluid. And fluid inlets may be formed in the upper and lower portions, respectively. Therefore, when the plate | board which a partition or a flange is formed in the upper and lower end surfaces of the pipe body which comprises the said heat-transfer part is combined, joined or integrally formed, a sealed space can be formed inside.

The fluid (cooling water) introduced into the fluid inlet is recovered through the pipe wall of the heat transfer part after the waste heat possessed by the exhaust gas and the solid particles is discharged outward through the fluid outlet. In this case, the fluid may be flowed in a natural convection method by a local temperature difference, but the fluid may be forced to the pump to make the flow of the fluid more smoothly.

In addition, the riser and the solid particle recovery tube embedded in the heat transfer portion are in communication with the separating and mixing portions formed on the upper and lower portions of the heat transfer portion, and the exhaust gas and / or the solid particles continue to circulate.

(2) The separating part is a place where the solid particles discharged from the rising pipe located at the upper portion of the heat transfer part are temporarily deposited when they hit the separation plate, and a part of the rising pipe extending from the heat transfer part protrudes, and the solid particles. Inlet (solid particle inlet) may be formed to supplement the.

③ The mixing part is a place where the solid particles dropped through the solid particle recovery pipe is mixed with the exhaust gas introduced through the exhaust gas inlet, and because the diameter of the supply pipe for supplying the exhaust gas is the same as that of the rising pipe, that is, the solid particle recovery pipe Since the outer tube having a built-in is formed larger than the supply tube, the mixing portion is in the form of a hopper having a relatively large upper end and a smaller diameter lower end. In this case, the supply pipe for supplying the exhaust gas may be a separate pipe separated from the rising pipe or the shape of the rising pipe extending downward, in the latter case the rising pipe is extended to ride the inner surface (inner wall) of the mixing portion It is preferable to further form a plurality of through holes in the riser so that the solid particles slid may be mixed with the flue gas flowing into the riser.

In addition, when the outer tube including the separating part, the heat transfer part, and the mixing part is plural, each outer tube may be a separately formed form or an integrally formed one tube.

In addition, in the waste heat recovery apparatus of the present invention, the solid particles are injected after the temperature of the water (fluid) reaches a temperature (about 45 ° C. to 60 ° C.) that can be operated without condensation in the heat transfer tube (heat transfer part) after the system is operated. When the newly replenished solid particles are transported by air or injected in the open state, the flow conditions of the inside are changed and the transport capacity of the solid particles is reduced. Therefore, it is desirable to provide a double valve at the connection portion so that the solid particles can be replenished in a state completely isolated from the outside air. At this time, the solid particle supply unit into which the solid particles are introduced is preferably installed at the top of the mixing unit.

In addition, when the waste heat recovery apparatus of the present invention is manufactured in a multi-tubular shape, the waste heat recovery apparatus may be manufactured in a configuration similar to a single-pipe type having one rising pipe, but a plurality of inlets in which the mixed air flow of the solid particles and the exhaust gas rise are formed. It is preferable to provide a separating plate, respectively, above the rising pipe protruding into the separating part. More preferably, in order to prevent the solid particles which rise with the exhaust gas from being deposited on the separating part, a separating plate made of a curved surface having a cone shape is formed.

In addition, if necessary, a hopper-shaped particle collection element may be installed to smoothly move particles from the separation unit to the solid particle collection tube (downcoming tube).

In addition, the waste heat recovery apparatus of the present invention by installing the inlet induction pipe in the form of a perforated plate to the lower portion of the riser, the lower space of the riser acts as a kind of plenum chamber to recover the static pressure and reduce the flow rate of the exhaust gas It is desirable to allow even flow conditions to be formed when the flue-gas passes through the vertical tube.

Hereinafter, on the basis of the accompanying drawings will be described in detail the waste heat recovery apparatus according to each embodiment of the present invention.

Example 1

1 is a plan view showing a waste heat recovery apparatus according to an embodiment of the present invention. As shown in the figure, the waste heat recovery apparatus 10 of the present embodiment is the mixing unit 20 for mixing the exhaust gas and the solid particles, the heat transfer unit 30 is coupled to the upper end of the mixing unit and the separation coupled to the upper end of the heat transfer unit It is comprised by the part 40.

The exhaust gas inlet unit 50 is coupled to the lower end of the mixing unit 20, and the exhaust gas discharge unit 60 is coupled to the upper end of the separation unit 40.

An industrial furnace for discharging the exhaust gas is connected to the side of the exhaust gas inlet 50, and a valve 520 for discharging the dust particles of the solid particles or the exhaust gas is installed at the lower side.

The exhaust gas discharged from the industrial furnace is introduced into the mixing unit 20 through the exhaust gas inlet 510 by the blower 530, and the exhaust gas introduced into the mixing unit is mixed with the solid particles to rise toward the heat transfer unit 30. Done.

The exhaust gas in which the solid particles are mixed, that is, the mixed airflow, transfers the waste heat to the inner wall of the riser while flowing along the riser 310 of the heat transfer unit, and the waste heat transferred to the inner wall is transferred to the fluid (cooling water) again. The temperature of the fluid rises.

In this process, the dust contained in the exhaust gas is adsorbed on the inner wall of the riser 310, but the adsorption of the dust mass naturally occurs because the solid particles contained in the mixed air rise while hitting or scratching the inner wall of the riser. Is prevented.

As such, the solid particles that rise while hitting or scraping the inner wall of the riser are hit by the separator 410 of the separator 40 and fall down, and the solid particles dropped are temporarily accumulated at the bottom of the separator. . In addition, the solid particles are also separated by the separator, but also separated by the pressure drop due to the difference in diameter between the riser and the separator. That is, in this embodiment, since the diameter of the separation portion is larger than the diameter of the riser, the flow rate of the exhaust gas discharged toward the separation portion through the riser is significantly reduced in the separation portion, thereby lowering the transport capacity of the solid particles, and the flow of the exhaust gas. When the direction changes, the solid particles are separated and removed from the mixed air stream by the difference in inertia force.

Thereafter, the exhaust gas from which the solid particles are removed is discharged to the outside through the exhaust gas discharge unit 60 coupled to the upper end of the separation unit 40, and the solid particles separated from the mixed air stream are recovered with the solid particle with a small amount of exhaust gas. Via the pipe 320 is conveyed back to the mixing portion 20 below. Then, the retransmitted solid particles are mixed with the newly introduced flue gas and floated again, and the solid particles circulate by repeating this process.

At this time, the re-transfer process (recovery process) of the solid particles is automatically made by the weight of the solid particles, the solid particles in contact with the high temperature exhaust gas in the process of floating along the riser is the solid particle recovery During the descent along the tube, secondary heat transfer occurs from the solid particles toward the fluid (cooling water) to heat the fluid.

In addition, the flange 700 formed in the mixing section 20, the heat transfer section 30 and the separation section 40 is fixed to each other by a conventional coupling means such as bolts, gasket (gasket) between the flange When the sealing means are fitted, water leakage is prevented.

2 is a cross-sectional view taken along the line AA of FIG. 1, the waste heat recovery apparatus of the present embodiment has a relatively small diameter solid particle recovery tube at a distance from one of the large rising tubes 310. A large number of 320 are provided around the riser.

On the other hand, in the present embodiment, a conventional pipe having a circular cross section is used as the riser 310, but a tube formed with a bend may be used to increase the heat transfer area, or several tubes may be used simultaneously.

In addition, in the present embodiment, the solid particle collection pipe 320 is arranged in a spiral around the rising pipe, but may be installed in other forms, and the cross-sectional shape may also be other than circular.

Example 2

Figure 3 shows a multi-tubular waste heat recovery apparatus according to a second embodiment of the present invention, the difference from the first embodiment is the number of the rising pipe-down pipe (solid particle recovery pipe) constituting the heat transfer portion is shown in FIG. More than the single tube type waste heat recovery system shown in Fig. 1. 벨 Bell mouse (not shown) is installed at the exhaust gas inlet to secure stable operability, and the diameter is reduced by reducing the diameter so that the connection part with the mixing part has a gentle curvature. The point is made to match the diameter of the pipe (not shown) and the valve is installed in the replenishment line of the solid particles so that the solid particles can be replenished in a state separated from the outside air. Accordingly, the present inventors omit the detailed description of the present embodiment by writing the same reference numerals for each component having the same function as the first embodiment.

Example 3

4 is a schematic structural view showing a multi-pipe waste heat recovery apparatus according to a third embodiment of the present invention, FIG. 5 is a sectional view taken along line BB of FIG. 4, and FIG. 6 is an upper structure of the riser tube shown in FIG. 5. It is shown.

As shown, the multi-pipe waste heat recovery device 10 of the present embodiment is a total of nine waste heat recovery unit consisting of four solid particle recovery pipe 320 per one rising pipe (310) to the outer tube of the rectangular cross section It is built-in and comprises the heat-transfer part 30.

The lower portion of the heat transfer unit 30 is provided with a mixing unit, an exhaust gas inlet unit, and a solid particle discharge valve 520 having the same configuration as that shown in Embodiments 1 and 2, and the exhaust gas inlet unit is shown in FIG. 9. One end of the exhaust gas inlet connected to is extended into the mixing portion, and a plurality of through holes are formed in the surface of the one end. In this case, the through hole serves to reduce the flow rate of the exhaust gas flowing into the mixing unit a little to create an even flow condition when the exhaust gas passes through the riser.

On the other hand, a separation part is provided in the upper part of the said heat transfer part, and the pipe is connected to the exhaust-gas discharge part connected with the said separation part. A blower is provided at any point of the pipe, and an orifice is formed inside the pipe between the blower and the exhaust gas discharge part.

In addition, as in the second embodiment described above, the replenishment line of the solid particles having valves 521 and 522 installed therein is connected to the separator so that the solid particles can be replenished in an isolated state from the outside. A diffuser 800 is installed at the bottom of the replenishment line, as shown, to allow the preheated solid particles to be evenly dispersed when introduced into the separator when stagnated between the two valves.

On the other hand, a plurality of circular through holes are formed in the upper end of the riser 310 protruding into the separation unit, and the external leakage of the solid particles is blocked while the exhaust gas is smoothly discharged by the through holes. Furthermore, in this embodiment, the wedge-shaped separator plate 410 is installed as a finishing material on the upper end of the ascending pipe so that the solid particles in the mixed air stream can be separated more smoothly.

In addition, in the present embodiment, after the data from the temperature sensor and the pressure sensor installed at the site through which the exhaust gas passes, the data from the injection of the solid particles to the discharge can be automated by feedback control. Accordingly, an automatic control system for controlling the operation timing of the valves 520, 521, and 522 and the blower was adopted.

Fig. 7 is a block diagram showing the operation mode of the shell-and-tube waste heat recovery apparatus described in Example 3, which shows the valve opening / closing timing and / or operating conditions during condensate discharge / particle injection / long-term operation / cleaning operation / particle discharge. .

Hereinafter, with reference to the drawings will be described the opening and closing time and / or operating conditions of the valve for each operation mode.

⑴Particle injection mode

In order to inject solid particles, the valve indicated by reference numeral 522 is opened for a predetermined time and then closed. In this way, the solid particles are discharged downward by the weight from the hopper containing the solid particles, but the solid particles are the conduit between these valves 521 and 522 because the valve indicated by reference numeral 521 is closed. The gas is stagnated for a while (stage 1 injection), and in this process, the exhaust gas discharged to the outside through the exhaust gas discharge part is discharged while heating the pipe, and the temperature of the solid particles is increased. The solid particle is injected into the separation unit by opening the valve indicated by (2 stage injection). At this time, the diffuser 800 of FIG. 10 is installed below the replenishment line of the solid particles so that the solid particles are evenly dispersed.

Therefore, the first stage injection prevents condensation on the surface of the solid particles generated when the cold solid particles are introduced into the heat transfer unit, and the second stage injection is performed in a state in which the valve 522 is closed. It does not flow into the separator, preventing disturbance of the internal flow field.

⑵Long term operation mode

When the difference between the internal pressures measured at the upper and lower ends of the riser is smaller than the set value, the valve indicated by reference numeral 522 is opened and closed for a predetermined time and then the valve indicated by reference numeral 521 as in the above-described particle injection mode. Is opened to further inject solid particles into the heat transfer unit.

In most cases, since the waste heat recovery apparatus of the present invention is hardly affected by the outside air by the double valve system, the internal pressure hardly changes in the normal operation state, so that automatic operation for a long time is possible.

운전 Cleaning operation mode

When the temperature measured at the exhaust gas discharge part during operation is higher than a set value in a state in which a part of the solid particles inside the waste heat recovery device is removed by opening and closing the valve at 520, the valves 521 and 522 are opened as in the operation mode. Open and close in the order specified.

Theoretically, the high temperature of the exhaust gas discharged from the waste heat recovery apparatus of this embodiment means that the heat transfer is not performed properly. In this case, the contaminated heat transfer surface is cleaned by injecting new solid particles.

⑷Particle discharge mode

If a certain period of time elapses during the long-term operation or if necessary to stop the operation in the state that the particles are circulated, the valve indicated by reference numeral 520 is opened for a sufficient time to remove these contaminated solid particles from the waste heat recovery device. Then, when the particle discharge mode is restarted, the particle injection mode is performed to fill solid particles.

Condensate discharge mode

When the inlet temperature of the fluid (circulating water or cooling water) heated while passing through the heat transfer unit is higher than or equal to the set temperature and the outlet temperature of the fluid is lower than or equal to the inlet temperature, the valve indicated by reference numeral 520 is opened and closed for a predetermined time.

In the initial operation of the waste heat recovery system, if the circulating water is not sufficiently heated, condensation occurs due to condensation when moisture contained in the flue gas comes into contact with the inner surface of the heat transfer unit. If the condensate is not discharged, dust and water droplets are entangled. The water droplets adhere to the inner surface of the heat transfer unit, or the water droplets aggregate with the solid particles, causing various problems in operation.

On the other hand, each operation mode described above may be made in software, that is, automatically by the automatic control system of the present embodiment, but also by a simple manual operation in which an operator presses a specific button.

In addition, the opening / closing time and operating conditions of the valve may be arbitrarily set by the user according to the size and use of the waste heat recovery device. For this purpose, the automatic control system may be equipped with specific software or D / B.

Example 4

Figure 8 shows a multi-tubular waste heat recovery apparatus according to another embodiment of the present invention, the configuration is almost the same except that the number of the riser tube is increased compared to the case of Example 3, so detailed description thereof will be omitted here. do.

As described above, since the waste heat recovery apparatus of the present invention does not have a distribution plate in the form of a porous plate for fluidizing solid particles, the pressure loss of the exhaust gas introduced into the waste heat recovery apparatus can be minimized, and the flow state inside the riser can be more stable. I can keep it. Therefore, there is no need to use a large-capacity blower to compensate for the pressure loss.

In addition, since the waste heat recovery apparatus of the present invention recovers waste heat firstly in the riser and secondly in the solid particle recovery tube, the heat recovery rate may be higher than that of the related art.

In addition, the waste heat recovery apparatus of the present invention has the advantage of preventing the disturbance and condensation of the internal flow field due to the solid particle injection by installing a double valve in the replenishment line of the solid particles and the exhaust gas is discharged through the replenishment line. have.

In particular, the present invention has the advantage that the various problems in operation can be solved without the operator's involvement by allowing the automatic control system to automatically set the opening and closing time and operating conditions of the valve. As a result, stable operation is possible in a wide operating range.

Claims (7)

A riser pipe through which exhaust gas and solid particles flow; A separation plate installed above the riser and separating the exhaust gas and the solid particles discharged from the riser; Upper and lower flanges disposed on upper and lower outer surfaces of the riser and having at least one hole formed on a surface thereof; Solid particle recovery pipes each having upper and lower ends connected to the holes of the upper and lower flanges; And An outer tube having the flange coupled to the upper and lower portions, respectively, having a fluid inlet and a fluid outlet at one side of the surface thereof, and a mixing space of exhaust gas and solid particles formed at the bottom thereof; Waste heat recovery device comprising a. The method of claim 1, The solid particle recovery pipe is waste heat recovery device, characterized in that installed spirally along the circumference of the riser. The method of claim 1, The mixing space is in communication with the riser and the solid particle recovery tube, waste heat recovery apparatus characterized in that the lower portion of the particle guide portion having a predetermined length in the lower portion. The method according to any one of claims 1 to 3, The waste heat recovery device A waste heat recovery apparatus, characterized in that a multi-tubular modular unit is defined as a riser-solid particle recovery tube. A heat transfer part through which waste heat of exhaust gas is transferred to circulating water; A mixing unit installed below the heat transfer unit so that the exhaust gas and the solid particles are introduced into the heat transfer unit in a mixed state; A separation unit installed above the heat transfer unit so that the exhaust gas discharged from the heat transfer unit and the solid particles are separated from each other; And A replenishment line of solid particles in communication with the separator with a double valve; Waste heat recovery device comprising a. The method of claim 5, wherein The heat transfer part is a waste heat recovery device, characterized in that a plurality of built-in waste heat recovery unit consisting of a riser and a solid particle recovery pipe. The method according to claim 5 or 6, Waste heat recovery device characterized in that the automatic control system for determining the opening and closing time of the valve is further installed.

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