KR102381714B1 - System that burns waste with flexibility in operating capacity - Google Patents

Abstract

An embodiment of the present invention provides a technique for increasing the amount of waste disposal and the efficiency of waste treatment in a system that generates energy by burning waste. According to an embodiment of the present invention, a waste-to-energy system with flexibility in operating capacity comprises: a combustion furnace for receiving fuel and performing combustion by using fluid sand and oxygen transfer particles as layer materials; a cyclone which is connected to the combustion furnace and receives the fluid sand, the oxygen transfer particles, and exhaust gas from the combustion furnace; a loop chamber connected to the cyclone, and for receiving a mixture containing the fluid sand and the oxygen transfer particles from the cyclone and transferring a part of the mixture to the combustion furnace; an external heat exchanger for receiving the remainder of the mixture from the loop chamber, cooling the mixture by exchanging heat between the mixture and a heat exchange fluid, and oxidizing the reduced oxygen transfer particles; and a valve unit formed between the combustion furnace and the external heat exchanger and for controlling the amount of the mixture flowing into the combustion furnace through the external heat exchanger.

Description

Waste-to-energy system with flexible operating capacity {SYSTEM THAT BURNS WASTE WITH FLEXIBILITY IN OPERATING CAPACITY}

The present invention relates to a waste-to-energy system in which operating capacity flexibility is secured, and more particularly, to a technology for increasing waste treatment amount and waste treatment efficiency in a system for converting waste into energy.

Currently, incinerators for waste treatment nationwide are being operated in a state in which the treatment capacity exceeds the capacity, but since the incinerator capacity excess treatment is not permitted by law, the demand for an eco-friendly waste treatment method is increasing.

Due to the characteristics of waste, the treatment of waste fuels with low calorific value is a problem due to the non-uniformity and heterogeneity of waste properties. Do.

In addition, since exhaust gas containing air pollutants emitted during incineration for waste treatment is always a problem in terms of acceptance by residents, a technology capable of reducing the exhaust gas emitted in this way is required.

In Korean Patent Registration No. 10-0699519 (Title of the Invention: Circulating Fluidized Bed Boiler for Combustion of Waste and RPF), the fuel stored in the fuel storage tank 1 is transferred to the combustion furnace 3 connected to the fuel injector 2 on the lower side. The cyclone (4) with the seal port (5) installed on the lower side by supply and combustion is connected to the external heat exchanger (6) and the convection heat transfer unit (7) from the upper side and from the center, and this convection heat transfer unit (7), absorption In the circulating fluidized bed boiler discharged through the chimney through the tower (9), the bag filter (10), and the washing tower (11), the seal port (5) and the external heat exchanger (6) are connected to the particle recirculation path (22) There is disclosed a circulating fluidized bed boiler exclusively for waste and RPF combustion, characterized in that the convection heat transfer unit 7 and the final superheater 28 installed inside the external heat exchanger 6 are connected.

Republic of Korea Patent Registration No. 10-0699519

An object of the present invention for solving the above problems is to increase the amount of waste processed in a system for converting waste into energy.

Another object of the present invention is to increase waste treatment efficiency by enabling the treatment of wastes having a low calorific value.

And, an object of the present invention is to perform temperature control in the combustion furnace by controlling the amount of flow sand re-introduced into the combustion furnace after being circulated.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. There will be.

The configuration of the present invention for achieving the above object includes: a combustion furnace that receives fuel and performs combustion using flowing sand and oxygen transfer particles as a layer material; a cyclone connected to the combustion furnace and receiving the flowing sand and the oxygen delivery particles and exhaust gas from the combustion furnace; a loop seal connected to the cyclone, receiving the mixture containing the flowing sand and the oxygen transfer particles from the cyclone, and transferring a portion of the mixture to the combustion furnace; an external heat exchanger that receives the remainder of the mixture from the loop seal, cools the mixture by performing heat exchange between the mixture and a heat exchange fluid, and oxidizes the reduced oxygen transfer particles; and a valve formed between the combustion furnace and the external heat exchanger and configured to control the amount of the mixture flowing through the external heat exchanger to the combustion furnace.

In an embodiment of the present invention, the valve unit may include a packing used to control the flow rate of the mixture, and a cooling fluid may flow into the valve unit to cool the packing.

In an embodiment of the present invention, the valve unit may be a rotary valve.

In an embodiment of the present invention, the external heat exchanger may further include a heat exchange unit having a portion positioned inside the external heat exchanger and providing a flow path to the heat exchange fluid.

In an embodiment of the present invention, a recirculation unit connected to the external heat exchanger, receiving air discharged from the external heat exchanger, and supplying a portion of the received air to the external heat exchanger may be further included.

In an embodiment of the present invention, it may further include a pump unit for flowing the air received from the recirculation unit or the air received from the outside to the lower portion of the external heat exchanger.

In an embodiment of the present invention, the oxygen transfer particle may be a metal oxide.

In the configuration of the present invention for achieving the above object, after the mixture is transferred from the cyclone to the loop chamber, a part of the mixture is transferred to the combustion furnace and the remainder of the mixture is transferred to the external heat exchanger. Step 1; a second step of performing heat exchange between the mixture and the heat exchange unit while passing the mixture through the external heat exchanger, and providing air to the mixture; a third step in which the reduced oxygen transfer particles included in the mixture are oxidized, and the mixture is discharged from the external heat exchanger and introduced into the valve unit; a fourth step of controlling the amount of the mixture passing through the valve unit by the operation of the valve unit; and a fifth step in which the mixture passing through the valve unit is supplied to the combustion furnace.

The effect of the present invention according to the above configuration is to increase the amount of oxygen in the combustion performed in the combustion furnace by using the oxidized oxygen transfer particles, and thereby increase the operation capacity of the combustion furnace to secure operation flexibility and convert it into fuel. The amount of waste used can be freely controlled.

In addition, an effect of the present invention is that, by increasing the oxygen content during pure oxygen combustion, it is possible to input waste having a low calorific value with a relatively high moisture content.

In addition, an effect of the present invention is that it is possible to increase the fuel input, thereby further increasing the temperature of the circulated flowing sand, and thus recovering relatively more heat of the flowing sand in the external heat exchanger.

And, the effect of the present invention is that the flow rate of the mixture (fluid and oxygen transfer particles) discharged from the external heat exchanger by the valve unit is controlled, so that the amount of air supplied to the lower chamber of the external heat exchanger can be minimized, Accordingly, it is possible to reduce wear and corrosion caused by the flow of the mixture (fluid yarn and oxygen transfer particles) in contact with the heat exchange unit inside the external heat exchanger.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a schematic diagram of a waste energy conversion system according to an embodiment of the present invention.
2 is a schematic diagram of an external heat exchanger according to an embodiment of the present invention.
3 is a graph showing the temperature of each of the cyclone, the loop seal and the external heat exchanger in each combustion condition (air combustion, pure oxygen combustion with increased oxygen content) according to an embodiment of the present invention.
4 is a graph showing the amount of heat input fuel in each combustion condition (air combustion, pure oxygen combustion with increased oxygen content) according to an embodiment of the present invention.
5 is a graph of pollutant emissions in each combustion condition (air combustion, pure oxygen combustion with increased oxygen content) according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in several different forms, and thus is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be “connected (connected, contacted, coupled)” with another part, it is not only “directly connected” but also “indirectly connected” with another member interposed therebetween. "Including cases where In addition, when a part "includes" a certain component, this means that other components may be further provided without excluding other components unless otherwise stated.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of a waste energy conversion system according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of an external heat exchanger 100 according to an embodiment of the present invention. As shown in FIGS. 1 and 2 , the waste energy conversion system of the present invention includes a combustion furnace 410 that receives fuel and performs combustion using flowing sand and oxygen transfer particles as a layer material; a cyclone 420 connected to the combustion furnace 410 and receiving flowing sand and oxygen transfer particles and exhaust gas from the combustion furnace 410; a loop seal 430 connected to the cyclone 420 , receiving a mixture containing flowing sand and oxygen transfer particles from the cyclone 420 , and transferring a portion of the mixture to the combustion furnace 410 ; an external heat exchanger 100 that receives the remainder of the mixture from the loop seal 430, cools the mixture by performing heat exchange between the mixture and the heat exchange fluid, and oxidizes the reduced oxygen transfer particles; and a valve unit 500 that is formed between the combustion furnace 410 and the external heat exchanger 100 and controls the amount of the mixture flowing to the combustion furnace 410 through the external heat exchanger 100; .

In addition, the waste-to-energy system of the present invention is connected to the external heat exchanger 100 , receives air discharged from the external heat exchanger 100 , and supplies a portion of the received air to the external heat exchanger 100 . A recirculation unit 200 may be further included. In addition, the waste-to-energy system of the present invention may further include a pump unit 300 for flowing the air received from the recirculation unit 200 or the air received from the outside to the lower portion of the external heat exchanger 100 .

In the cyclone 420 , the circulating flow sand discharged from the combustion furnace 410 and the reduced oxygen transfer particles may be mixed to form a mixture. Here, the combustion furnace 410 and the cyclone 420 may be configured according to the prior art, and the waste energy conversion system of the present invention is a pure oxygen circulating fluidized bed combustion system, in addition to the configuration described in detail below, a pure oxygen circulating fluidized bed. Other prior art configurations related to combustion systems may be included.

In the waste-to-energy system of the present invention, waste can be used as a fuel. Here, as waste, all materials that are no longer needed in daily life or business activities, such as garbage, combustible ash, SRF, medical waste, and plastic waste, may be used. However, it goes without saying that the fuel is not limited to waste and any fuel applicable to the circulating fluidized bed such as coal and biomass may be used.

The waste-to-energy system of the present invention aims to secure the operational capacity flexibility (expansion of the operating capacity range) of the waste-to-energy facility without additional facility expansion, and the implementation means for solving the purpose will be described in detail below. do.

The oxygen transporting particles may be metal oxides. That is, the oxygen-transferring particles are oxidized by absorbing oxygen in a condition in which there is a lot of oxygen (or air), and in a condition in which there is a lot of fuel, the particles in the form of metal oxide are mainly used as particles that burn the fuel by consuming the oxygen contained in the particles in the condition of a lot of fuel. there is.

As shown in FIG. 1 , metal oxide (Me _x O _y ) or oxygen carrier particles of natural minerals may be supplied together with fuel to a combustion furnace 410 (CFB combustor). . The oxygen transfer particles may be heated in the combustion furnace 410 , and as a reduction reaction is performed on the oxygen transfer particles supplied to the combustion furnace 410 , oxygen is released and some of them may be used as an oxidizing agent for combustion.

As inexpensive oxygen transfer particles, red mud, bauxite, iron ore, oxide scale, ilmenite, etc. may be used, and oxides or composites thereof may be used. And, in the case of artificially manufactured, metals such as Ni, Co, Cu, Fe, Mn, W, Mo, Cr, Nb, V, Ce, In, Sn, and their respective oxides and composites may be used. Here, the composite may include a composite of each oxide.

Here, when the oxygen transfer particles are metal oxides, the metal oxide may pass through the combustion furnace 410 in a reduced state (Me _x O _y-1 ). Here, aO ₂ in FIG. 1 may mean an oxide resulting from combustion of fuel. Hereinafter, the case where the oxygen transporting particles are metal oxides will be described.

After combustion, the reduced oxygen transfer particles (Me _x O _y-1 ) may be introduced into the loop seal 430 after passing through the cyclone 420 after forming a mixture with the flowing sand and the like. In addition, when the mixture is discharged from the loop seal 430 and introduced into the external heat exchanger 100 , the reduced oxygen transfer particles may also pass through the loop seal 430 and then be introduced into the external heat exchanger 100 . In addition, the oxygen transfer particles reduced in the external heat exchanger 100 may be oxidized by capturing some oxygen in the air supplied from the lower portion of the external heat exchanger 100 . In this way, the oxygen transfer particles (Me _x O _y ) changed to the initial state supplied to the combustion furnace 410 after being oxidized in this way are discharged from the external heat exchanger 100 and pass through the valve unit 500 and then the combustion furnace 410. It can be circulated back to the supply. The flow path of such oxygen transfer particles will be described in more detail below.

The oxygen content in the oxidizer including oxygen supplied in the combustion furnace 410 and supplied through the oxygen transfer particles may be 60% or more (O ₂ ≥ 60 vol.% in the oxidant). Here, the oxidizing agent may be a gas such as air. By supplying oxygen in the combustion furnace 410 using oxygen transfer particles instead of a part of the flowing sand, the oxygen content in the oxidizing agent may be formed to be 60% or more.

By increasing the amount of oxygen generated from the oxygen transfer particles as described above, it is possible to increase the amount of oxygen in the oxidizer in the combustion performed in the combustion furnace 410 , thereby securing flexibility in the operation capacity of the combustion furnace 410 . Specifically, it is possible to increase the amount of pure oxygen that can be supplied to the combustion furnace 410 by increasing the amount of oxygen generated from the oxygen transfer particles, and accordingly, the combustion furnace 410 operating capacity range by increasing the combustion furnace 410 operating capacity. It is possible to increase the input amount of waste used as fuel by increasing the And, by increasing the oxygen content during pure oxygen combustion as described above, it may be possible to input waste having a low calorific value with a relatively high moisture content.

As described above, the fuel input amount (waste input amount) can be increased, so that the temperature of the circulating flow yarn can be further increased, and thus, relatively more heat of the flow yarn can be recovered in the external heat exchanger 100 . In addition, steam by heat recovered from the external heat exchanger 100 can be used in the waste energy conversion system of the present invention, and in particular, can be used as heat for drying fuel (waste) having a high water content. In addition, waste combustion efficiency may be increased by burning waste containing moisture and having a low calorific value as described above.

The external heat exchanger 100 is an upper chamber 110 that is formed on the upper part of the external heat exchanger 100 and provides a space in which the mixture flows, a space formed in the lower part of the upper chamber 110 and in which the introduced air flows. A plurality of nozzles 131 formed between the lower chamber 120 and the upper chamber 110 and the lower chamber 120 for providing A dispersing plate 130 may be provided.

In addition, the external heat exchanger 100 may further include a heat exchange unit 140 coupled to the upper chamber 110 so that a portion is located inside the upper chamber 110 and provides a flow path to the heat exchange fluid, In the heat exchanger 100 , one portion is formed through the lower chamber 120 and the distribution plate 130 , the other portion is connected to the valve portion 500 , and a flow path is provided to the mixture passing through the upper chamber 110 . It may further include a heat exchanger discharge pipe 151 provided, and a heating air discharge pipe 152 through which air injected through the nozzle 131 is discharged through a pipe formed on the upper part of the upper chamber 110 .

The pump unit 300 may provide a force for flowing the heated air received from the recirculation unit 200 or the air received from the outside (atmosphere) into the lower chamber 120 . Here, the pump unit 300 may receive heated air from the recirculation unit 200 . In addition, the pump unit 300 may be connected to the lower chamber 120 by the pump pipe 310 , and may be connected to the recirculation unit 200 by the recirculation discharge pipe 210 .

In the waste-to-energy system of the present invention, one end is coupled to the loop seal 430 and the other end is coupled to the combustion furnace 410 , and a second loop seal discharge pipe provides a flow path to a portion of the mixture that has passed through the loop seal 430 . 432 may be formed. In addition, a first loop seal discharge pipe 431 having one end coupled with the loop seal 430 and the other end coupled with the external heat exchanger 100 and providing a flow path to the remainder of the mixture that has passed through the loop seal 430 will be formed. can Here, the reduced oxygen transfer particles in the mixture passing through the first loop seal discharge pipe 431 may be introduced into the upper chamber 110 of the external heat exchanger 100 . Then, the mixture passing through the second loop seal discharge pipe 432 may be fed back into the combustion furnace 410 .

1 and 2 , the heat exchange unit 140 may be formed in a shape of a pipe through which a heat exchange fluid passes, but is not limited thereto, and may be formed in other shapes capable of heat exchange. When the heat exchange unit 140 is formed in the shape of a pipe through which the heat exchange fluid flows, a portion of the heat exchange unit 140 positioned in the upper chamber 110 may have a zigzag shape bent several times. In addition, the remaining portion of the heat exchange unit 140 may be connected to a device (such as a heating device) that emits heat by supplying a heat exchange fluid that has received heat from the mixture.

One end of the heat exchanger discharge pipe 151 may be coupled to the perforated portion of the distribution plate 130 , and the other end of the heat exchanger discharge pipe 151 may be coupled to the valve unit 500 , and accordingly, the heat exchanger discharge pipe 151 One portion may be formed through the lower chamber 120 , and the remaining portion of the heat exchanger discharge pipe 151 may be exposed to the outside.

And, the air introduced into the external heat exchanger 100 from the outside of the external heat exchanger 100 may be introduced from the lower part of the external heat exchanger 100 upward to perform the function of a fluidization medium. The pump unit 300 may supply the sucked air to the lower chamber 120 , and the supplied air may be sprayed toward the upper chamber 110 through the nozzle 131 of the dispersion plate 130 . Here, the perforated portion of the distribution plate 130 is formed in the central portion of the distribution plate 130 so that one end of the heat exchanger discharge pipe 151 may be coupled to the central portion of the distribution plate 130 , and the heat exchanger discharge pipe 151 ) around one end of the nozzle 131 may be formed.

As described above, oxygen is supplied to the reduced oxygen transfer particles (Me _x O _y-1 ) after combustion by the air flowing into the lower chamber 120 of the external heat exchanger 100, so that the reduced oxygen transfer particles are again It can be changed to an initial state of oxygen transfer particles (Me _x O _y ). And, since the air flowing into the lower chamber 120 of the external heat exchanger 100 is discharged to the upper chamber 110 of the external heat exchanger 100 and then discharged to the recirculation unit 200, the external heat exchanger 100 ) can minimize the mixing ratio of air to the mixture passing through, and as a result, when the mixture is supplied back to the combustion furnace 410, exhaust recirculation (FGR) during pure oxygen combustion in the waste energy conversion system of the present invention By minimizing the mixing ratio of high-purity CO ₂ and air, a phenomenon in which the purity of high-purity CO ₂ is reduced can be prevented.

After being injected into the upper chamber 110 from the lower chamber 120 , the air heated by the mixture may be discharged through the heating air discharge pipe 152 . In addition, the air flowing along the heated air discharge pipe 152 may be introduced into the recirculation unit 200 . Here, the recirculation unit 200 may transfer a portion of the heated air received from the external heat exchanger 100 to the pump unit 300 and discharge the rest of the heated air. Here, the heated air may be high-temperature air in a state in which oxygen is partially consumed while oxidizing the reduced oxygen transfer particles.

Accordingly, heated air may be supplied to the lower chamber 120 by the pump unit 300 or mixed air in which the heated air and external air are mixed may be supplied to the lower chamber 120 . Accordingly, since heated air or mixed air is injected into the upper chamber 110 , and air having a higher temperature than when only external air is supplied to the upper chamber 110 , is injected into the upper chamber 110 , the upper chamber 110 . ) by minimizing a decrease in the internal temperature, it is possible to increase the heat recovery efficiency by the heat exchange unit 140 .

In addition, the heat of the high-temperature fluidized sand at 800°C that passes through the loop seal 430 and moves to the external heat exchanger 100 is recovered using the heat exchange unit 140 , and then the fluidized sand can be supplied to the combustion furnace 410 . In this case, by controlling the flow amount, flow rate, temperature, etc. of the heat exchange fluid passing through the heat exchange unit 140, the temperature of the flow yarn passing through the external heat exchanger 100 can also be controlled, and accordingly, the temperature is As the controlled flowing sand flows into the combustion furnace 410 and the temperature in the combustion furnace 410 is adjusted, the temperature in the combustion furnace 410 according to the fuel input is formed suitable for combustion, so that stable pure oxygen combustion can be performed. there is.

1, the heat exchange fluid discharged from the heat exchange unit 140 flows along the heat exchange discharge pipe 610 connected to the outlet of the heat exchange unit 140 to dry the fuel (solid fuel) ( not shown) may be supplied. Then, the heat exchange fluid cooled by being used to dry fuel (waste) while passing through the fuel drying unit (not shown) flows along the heat exchange inlet pipe 620 connected to the inlet of the heat exchange unit 140 to flow through the heat exchange unit 140 . ) and can be heated by the heat of the flowing yarn. In this way, by drying the waste, which is fuel, using the heat of the floating sand, and then supplying the fuel to the combustion furnace 410, the combustion efficiency of the fuel is increased, thereby increasing the overall operating efficiency of the waste-to-energy system of the present invention.

The valve unit 500 may include a packing used for controlling the flow rate of the mixture, and a cooling fluid may flow into the valve unit 500 to cool the packing. Here, the valve unit 500 may be a rotary valve. As described above, one side of the valve unit 500 may be coupled to the heat exchanger discharge pipe 151, and the other side of the valve unit 500 is coupled to one end of the valve sub-pipe 510 in the shape of a tube, and the valve sub-pipe 510. The other end of the is coupled to the lower portion of the combustion furnace 410, the mixture discharged from the valve unit 500 may be supplied to the combustion furnace 410 after flowing along the valve auxiliary pipe (510).

In the waste energy conversion system of the present invention, which is a pure oxygen circulating fluidized bed combustion system, as a method to increase efficiency, the oxygen concentration in the oxidizer is increased by minimizing the exhaust gas recirculation amount with the same oxygen input amount. In this case, the fuel input amount is increased , it is possible to perform temperature control in the combustion furnace 410 for a stable pure oxygen combustion operation.

Specifically, after the heat of the high temperature (800° C.) flowed yarn that passes through the loop seal 430 and moves to the external heat exchanger 100 is recovered in the heat exchange unit 140, the heat is recovered and the temperature of the flowed yarn is lowered ( 300° C. or less) may be discharged from the external heat exchanger 100 and introduced into the valve unit 500 . And, the amount of flowing sand in the mixture passing through the valve part 500 is adjusted by the operation of the valve part 500 so that the flowing sand is circulated to the combustion furnace 410 by a certain amount for temperature control of the combustion furnace 410 . can be controlled Accordingly, when the fuel input amount in the combustion furnace 410 is increased, it is possible to prevent a sudden decrease in the temperature inside the combustion furnace 410 to implement stable pure oxygen combustion.

As the flow yarn having a significant temperature even after heat recovery as described above passes through the inside of the valve unit 500 , the packing installed inside the valve unit 500 may be damaged or deformed by the heat of the flow yarn. In order to prevent such a phenomenon, a cooling fluid may be introduced into the packing to cool the packing, and carbon dioxide or recirculated exhaust gas in the combustion system of the present invention may be used as the cooling fluid.

And, by supplying the cooling fluid to the packing, the inflow of outside air into the valve part 500 can be prevented. In addition, since the mixture discharged from the external heat exchanger 100 is controlled by the valve unit 500, the amount of air supplied to the lower chamber 120 of the external heat exchanger 100 can be minimized, and accordingly, By minimizing the amount of the internal fluidization medium of the external heat exchanger 100 , it is possible to reduce wear and corrosion caused by the flow of the fluidized sand in the mixture in contact with the heat exchange unit 140 .

3 is a cyclone 420, a loop seal 430 and an external heat exchanger 100 in each combustion condition (air combustion, pure oxygen combustion with increased oxygen content) according to an embodiment of the present invention, respectively. This is a graph of temperature. As shown in FIG. 3 , combustion is performed in the combustion furnace 410 while changing the respective combustion conditions according to the operating time of the combustion furnace 410 , so that the cyclone 420 and the loop seal 430 are performed. And the temperature of each time of the external heat exchanger 100 was measured. 3, graph a shows the temperature change of the solid mixture (mainly including flow sand) passing through the cyclone 420 (Cyclone), and graph b shows the change in temperature of the mixture introduced into the loop seal 430 (Loop-seal). The temperature change is shown, the c graph shows the temperature change of the mixture in the vicinity of the dispersion plate 130 in the upper chamber 110 of the external heat exchanger 100 (EHE), and the d graph shows the external heat exchanger 100 (EHE). It represents the temperature change of the mixture passing through the heat exchanger discharge pipe 151 after passing through the upper chamber 110 of the.

In FIG. 3 , first, pre-heating of the combustion furnace 410 using LNG fuel was performed for the first 4 hours. In this case, the temperature of the combustion furnace 410 and the flowing sand rises over time, and the heated flowing sand is introduced into the cyclone 420 and the loop seal 430 in response to the cyclone 420 and the loop. The temperature of the seal 430 may increase. However, the temperature change may be insignificant because the flowing sand is not yet circulated in the external heat exchanger 100 .

Next, from 4 hours to 9.5 hours, the LNG supply is stopped, solid fuel is supplied to the combustion furnace 410, and oxygen for operation with an oxygen content of 60% or more in the gas supplied to the combustion furnace 410 in a pure oxygen combustion atmosphere was supplied to perform pre-heating (Oxy Pre-heating). In this case, the temperature of the combustion furnace 410 and the flowing sand rises over time, and the heated flowing sand is introduced into the cyclone 420 and the loop seal 430 in response to the cyclone 420 and the loop. The temperature of the seal 430 may increase. In addition, the flowing sand circulates to the external heat exchanger 100 to increase the temperature of the external heat exchanger 100 .

From 9.5 hours to 13.5 hours, solid fuel is supplied to the combustion furnace 410, and an oxidizing agent with an oxygen content of 60% or more (O ₂ ≥ 60 vol.% in the oxidant) is supplied to the combustion furnace 410 for combustion (Oxy- fired (60%)) was carried out. In this case, the temperature of the cyclone 420 may be formed at 800 ° C. or higher, the temperature of the loop seal 430 may also be formed at 800 ° C. or higher, and the upper chamber 110 of the external heat exchanger 100 . Heat exchange may be performed in the internally installed heat exchange unit 140 , so that the temperature of the mixture near the dispersion plate 13 of the external heat exchanger 100 can be cooled to 270 ^o C, and the flow sand by the valve unit 500 The amount of the mixture may be adjusted and supplied to the combustion furnace 410 . Accordingly, the temperature of the combustion furnace 410 may be maintained at 850° C. or higher.

After 13.5 hours, the solid fuel was supplied to the combustion furnace 410 and air was supplied to the combustion furnace 410 to perform air-fired. Here, the flow sand mixture circulated from the combustion furnace 410 to the cyclone 420 , the loop seal 430 and the external heat exchanger 100 is the cyclone 420 , the loop seal 430 and the combustion in the combustion furnace 410 . Since it is circulated to the furnace 410 , the operation of the external heat exchanger 100 may be stopped and the temperature of the external heat exchanger 100 may rapidly decrease.

As shown in FIG. 3, when an oxidizing agent having an oxygen content of 60% or more (O ₂ ≥ 60 vol.% in the oxidant) is supplied to the combustion furnace 410 together with the fuel, the cyclone 420 and the loop seal ( It can be seen that the temperature of the flow yarn passing through 430 is maintained at 750° C. or higher, and it can be confirmed that the temperature of the flow yarn is reduced to 270° C. by heat exchange with the heat exchange unit 140, and accordingly, the Oxy-fired section It can be seen that the heat recovery efficiency is the greatest due to the largest amount of heat exchange.

4 is a graph of the amount of fuel input under each combustion condition (air combustion, pure oxygen combustion with increased oxygen content) according to an embodiment of the present invention, where, for each of Oxy-fired and Air-fired The matters are the same as those described in the description of FIG. 3 . And, the same solid fuel as in FIG. 3 was used.

As shown in FIG. 4 , in the air-fired condition, fuel having 75 kWh of heat is burned in the combustion furnace 410, whereas in the oxygen-fired condition, fuel having 150 kWh of heat in the combustion furnace 410 is burned. Combustion can be confirmed. According to the graph interpretation of FIG. 4 , when an oxidizing agent having an oxygen content of 60% or more (O ₂ ≥ 60 vol.% in the oxidant) is supplied to the combustion furnace 410 together with the fuel, more than when air is supplied It can be confirmed that an amount of fuel can be processed.

5 is a graph of pollutant emissions in each combustion condition according to an embodiment of the present invention. In Figure 5, a is a graph for sulfur dioxide (SO ₂ ), b is a graph for carbon monoxide (CO), c is a graph for nitrogen monoxide (NO). As shown in FIG. 5 , it can be confirmed that the emission of each pollutant is significantly reduced in the oxygen-fired condition than in the air-fired condition.

It is possible to construct a cogeneration system including the waste-to-energy system of the present invention configured as described above. As described above, in the waste-to-energy system of the present invention, a relatively increased amount of waste can be treated, so that the combustion efficiency is increased and the amount of pollutants generated is reduced. there is.

Hereinafter, a waste energy conversion method using the waste energy conversion system of the present invention will be described.

First, in the first step, after the mixture is transferred from the cyclone 420 to the loop seal 430 , a part of the mixture is transferred to the combustion furnace 410 and the remainder of the mixture is transferred to the external heat exchanger. It can be passed to (100). And, in the second step, as the mixture passes through the external heat exchanger 100 , heat exchange is performed between the mixture and the heat exchange unit 140 , and air may be provided to the mixture.

Next, in the third step, the reduced oxygen transfer particles included in the mixture may be oxidized, and the mixture may be discharged from the external heat exchanger 100 and introduced into the valve unit 500 . And, in the fourth step, the amount of the mixture passing through the valve unit 500 may be controlled by the operation of the valve unit 500 . After that, in a fifth step, the mixture passing through the valve part 500 may be supplied to the combustion furnace 410 . The remainder of the waste to energy method of the present invention as described above is the same as the matter described in the waste to energy system of the present invention.

The above description of the present invention is for illustration, and those of ordinary skill in the art to which the present invention pertains can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

100: external heat exchanger 110: upper chamber
120: lower chamber 130: dispersion plate
131: nozzle 140: heat exchange unit
151: heat exchanger exhaust pipe 152: heated air exhaust pipe
200: recirculation unit 210: recirculation discharge pipe
300: pump unit 310: pump pipe
410: combustion furnace 420: cyclone
430: loop seal 431: first loop seal discharge pipe
432: second loop seal discharge pipe 500: valve part
510: valve auxiliary pipe 610: heat exchange exhaust pipe
620: heat exchange inlet pipe

Claims (9)

a combustion furnace that receives fuel and performs combustion using fluid sand and oxygen transfer particles as a layer material;
a cyclone connected to the combustion furnace and receiving the flowing sand and the oxygen delivery particles and exhaust gas from the combustion furnace;
a loop seal connected to the cyclone, receiving the mixture containing the flowing sand and the oxygen transfer particles from the cyclone, and transferring a portion of the mixture to the combustion furnace;
an external heat exchanger that receives the remainder of the mixture from the loop seal, cools the mixture by performing heat exchange between the mixture and a heat exchange fluid, and oxidizes the reduced oxygen transfer particles; and
a valve part formed between the combustion furnace and the external heat exchanger and controlling the amount of the mixture flowing to the combustion furnace through the external heat exchanger; and
The valve unit includes a packing used to control the flow rate of the mixture, and a cooling fluid flows into the valve unit to cool the packing.
delete The method according to claim 1,
The valve unit is a rotary valve (Rotary valve), characterized in that the operating capacity flexibility is secured waste energy system.
The method according to claim 1,
The external heat exchanger, a waste to energy system with secured operating capacity flexibility, characterized in that a portion is located inside the external heat exchanger and further comprises a heat exchange unit that provides a flow path to the heat exchange fluid.
The method according to claim 1,
Waste energy conversion system connected to the external heat exchanger, receiving the air discharged from the external heat exchanger, and further comprising a recirculation unit for supplying a part of the received air to the external heat exchanger .
6. The method of claim 5,
Waste-to-energy system with secured operating capacity flexibility, characterized in that it further comprises a pump unit for flowing the air received from the recirculation unit or the air received from the outside to the lower part of the external heat exchanger.
The method according to claim 1,
The oxygen transfer particle is a waste energy system, characterized in that the metal oxide is secured operating capacity flexibility.
8. A combined heat and power generation system comprising a waste-to-energy system in which the operating capacity flexibility according to any one of claims 1, 3 to 7 is secured.
In the waste energy conversion method using the waste energy conversion system in which the operating capacity flexibility of claim 4 is secured,
a first step of transferring the mixture from the cyclone to the loop chamber, transferring a portion of the mixture to the combustion furnace and transferring the remainder of the mixture to the external heat exchanger;
a second step of performing heat exchange between the mixture and the heat exchange unit while passing the mixture through the external heat exchanger, and providing air to the mixture;
a third step in which the reduced oxygen transfer particles included in the mixture are oxidized, and the mixture is discharged from the external heat exchanger and introduced into the valve unit;
a fourth step of controlling the amount of the mixture passing through the valve unit by the operation of the valve unit; and
A fifth step of supplying the mixture that has passed through the valve unit to the combustion furnace;

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