Incineration system and heating medium supply control method

Abstract

To provide an incineration system and a heating medium supply control method capable of suppressing deterioration due to an elevated temperature of a heating medium.SOLUTION: An incineration system includes a post-combustion furnace for burning gas generated along with thermal decomposition of an incinerated object. The post-combustion furnace includes a heat transfer pipe capable of recovering thermal energy generated through combustion of gas by causing a heating medium to flow inside. The incineration system further includes: a supply device that supplies the heating medium into the heat transfer pipe; and a control device that regulates flow rate of the heating medium within the heat transfer pipe by controlling the supply device. The control device acquires a first temperature of the heat transfer pipe, and controls the supply device on the basis of the acquired first temperature so that the heating medium flows within the heat transfer pipe at flow rate causing the first temperature to become a predetermined temperature or lower.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to an incineration system and a method for controlling heat medium supply. [Background technology]

[0002] In an incineration system (hereinafter simply referred to as an incineration system) that incinerates materials to be incinerated, for example, a heat medium is used to recover the thermal energy of the exhaust gas discharged from the incinerator.The incineration system then uses the recovered thermal energy for other purposes, such as raising the temperature of the air used to incinerate the materials to be incinerated (hereinafter also referred to as combustion air) (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-280707 Summary of the Invention [Problem to be solved by the invention]

[0004] In the incineration system described above, it is desirable to suppress deterioration of the heat transfer medium due to high temperatures, for example. [Means for solving the problem]

[0005] The incineration system disclosed herein includes a post-combustion furnace that combusts gas generated by the thermal decomposition of the material to be incinerated. The post-combustion furnace has heat transfer tubes that can recover thermal energy generated by the combustion of the gas by flowing a heat medium inside the furnace. The post-combustion furnace further includes a supply device that supplies the heat medium into the heat transfer tubes, and a control device that adjusts the flow rate of the heat medium inside the heat transfer tubes by controlling the supply device. The control device acquires a first temperature of the heat transfer tubes, and based on the acquired first temperature, controls the supply device so that the heat medium flows inside the heat transfer tubes at a flow rate that will make the first temperature equal to or lower than a predetermined temperature. [Effects of the Invention]

[0006] According to the incineration system and heat transfer medium supply control method disclosed herein, it is possible to suppress deterioration of the heat transfer medium due to high temperatures. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of an incineration system 100 according to the first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of the incineration system 100 according to the first embodiment. [Figure 3] FIG. 3 is a diagram illustrating the hardware configuration of the control device 10. As shown in FIG. [Figure 4] FIG. 4 is a flowchart illustrating combustion control in the first embodiment. [Figure 5] FIG. 5 is a diagram illustrating the measurement position of the first temperature. [Figure 6] FIG. 6 is a diagram illustrating an example of the configuration of an incineration system 100 according to the second embodiment. [Figure 7] FIG. 7 is a flowchart illustrating combustion control in the second embodiment. [Figure 8] FIG. 8 is a diagram illustrating a specific example of combustion control in the second embodiment. [Figure 9] FIG. 9 is a diagram illustrating a specific example of combustion control in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, such descriptions should not be interpreted in a limiting sense, and do not limit the subject matter described in the claims. Furthermore, various changes, substitutions, and modifications can be made without departing from the spirit and scope of the present disclosure. Furthermore, different embodiments can be combined as appropriate.

[0009] [Incineration system 100 in the first embodiment] First, an incineration system 100 according to a first embodiment will be described. Figures 1 and 2 are diagrams illustrating an example of the configuration of the incineration system 100 according to the first embodiment. Note that the arrangement, length, and number of pipes shown below are merely examples and are not limited to these. In addition, the following description will be given of a case where the material to be incinerated is sewage sludge (hereinafter simply referred to as sludge).

[0010] 1, the incineration system 100 includes, for example, an incinerator 1, a post-combustion furnace 2, and a heat utilization facility 3. The incineration system 100 also includes, for example, a blower B1, a blower B11, a blower B12, and a pump P.

[0011] Each of the blower B1, the blower B11, and the blower B12 is, for example, a device having a function of blowing air, such as a fan or a blower. Also, the blower B11 and the blower B12 may be, for example, a single blower.

[0012] The incinerator 1 is, for example, a furnace (gasification furnace or carbonization furnace) that generates pyrolysis gas G1 (hereinafter also simply referred to as gas G1) by incinerating and pyrolyzing sludge (dehydrated cake) supplied via a pipe L11. The pipe L11 is, for example, a pipe that connects the incinerator 1 with upstream equipment (for example, a sludge dryer). Specifically, the incinerator 1 is, for example, a fluidized bed incinerator, and has a so-called fluidized bed 1a. The pyrolysis gas G1 is then supplied to a post-combustion furnace 2 via the pipe L1. The pipe L1 is, for example, a pipe that connects an outlet side of the incinerator 1 for the pyrolysis gas G1 with an inlet side of the post-combustion furnace 2 for the pyrolysis gas G1.

[0013] The following description will be given assuming that the incinerator 1 is a fluidized bed incinerator, but the incinerator 1 is not limited to this. Specifically, the incinerator 1 may be, for example, various types of incinerators other than a fluidized bed incinerator.

[0014] The blower B1 supplies combustion air to the incinerator 1 via, for example, a pipe L21. The pipe L21 is, for example, a pipe that connects the outlet side of the blower B1 with the inlet side of the incinerator 1 for combustion air.

[0015] The post-combustion furnace 2 is, for example, a downstream facility of the incinerator 1, and is a furnace that combusts the pyrolysis gas G1 supplied from the incinerator 1. Specifically, the post-combustion furnace 2 generates exhaust gas G2 by, for example, completely combusting the pyrolysis gas G1 supplied from the incinerator 1. The exhaust gas G2 is then supplied to downstream equipment (not shown) of the post-combustion furnace 2, for example, via a pipe L2. The pipe L2 is, for example, a pipe that connects the outlet side of the post-combustion furnace 2 for the exhaust gas G2 with the inlet side of the downstream equipment of the post-combustion furnace 2 for the exhaust gas G2.

[0016] The downstream equipment of the post-combustion furnace 2 may include, for example, a heat exchanger (not shown) that recovers the thermal energy of the exhaust gas G2, a white smoke prevention air preheater (not shown) that generates heated air (white smoke prevention air) that prevents water vapor contained in the exhaust gas G2 from appearing as white smoke, a dust collector (not shown) that collects impurities from the exhaust gas G2, and a filter (not shown) that removes SO from the exhaust gas by contacting it with an agent. X and the like.

[0017] The post-combustion furnace 2 has, for example, a combustion chamber 21 and a heat recovery chamber 22 that communicates with the combustion chamber 21 inside.

[0018] The combustion chamber 21 combusts, for example, a part of the pyrolysis gas G1 supplied from the incinerator 1. The pyrolysis gas G1 combusted in the combustion chamber 21 is then supplied to, for example, the heat recovery chamber 22.

[0019] The blower B11 supplies combustion air to the combustion chamber 21 via, for example, a pipe L31. The pipe L31 is, for example, one or more pipes that connect the combustion air outlet side of the blower B11 and the combustion air inlet side of the combustion chamber 21.

[0020] That is, the combustion chamber 21 combusts the pyrolysis gas G1 supplied from the incinerator 1 by using combustion air supplied from the blower B11, for example.

[0021] The heat recovery chamber 22, for example, combusts (completely combusts) the pyrolysis gas G1 supplied from the incinerator 1 and recovers the thermal energy generated by the combustion of the pyrolysis gas G1. The exhaust gas G2 generated in the heat recovery chamber 22 is then supplied to downstream equipment of the post-combustion furnace 2, for example.

[0022] The blower B12 supplies combustion air to the heat recovery chamber 22 via, for example, a pipe L32. The pipe L32 is, for example, one or more pipes that connect the combustion air outlet side of the blower B12 and the combustion air inlet side of the heat recovery chamber 22.

[0023] That is, the heat recovery chamber 22 burns (completely combusts) the pyrolysis gas G1 supplied from the combustion chamber 21 by using combustion air supplied from the blower B12, for example.

[0024] The combustion chamber 21 may generate exhaust gas G2 by completely combusting the pyrolysis gas G1 supplied from the incinerator 1. In this case, the exhaust gas G2 generated in the combustion chamber 21 may be supplied to downstream equipment of the post-combustion furnace 2 via the heat recovery chamber 22, for example.

[0025] Furthermore, for example, heat transfer pipes 2a through which the heat medium H flows are installed on the wall surface (inner wall) of the heat recovery chamber 22. The heat transfer pipes 2a increase the temperature of the heat medium H by recovering, for example, the thermal energy of the pyrolysis gas G1 (exhaust gas G2) combusted in the heat recovery chamber 22. That is, the heat transfer pipes 2a function as a heat exchanger that recovers, for example, the thermal energy of the pyrolysis gas G1 (exhaust gas G2).

[0026] Specifically, the heat transfer tube 2a is, for example, a tube (for example, a single tube) provided continuously along the wall surface of the heat recovery chamber 22. The heat transfer tube 2a raises the temperature of the heat transfer medium H by the thermal energy of the pyrolysis gas G1 (exhaust gas G2), for example, by causing the heat transfer medium H supplied to the heat recovery chamber 22 from outside the heat recovery chamber 22 to flow along the wall surface of the heat recovery chamber 22. Thereafter, the heat transfer tube 2a supplies the heat transfer medium H, whose temperature has been raised by the thermal energy, to the outside of the heat recovery chamber 22.

[0027] The pipe L32 may be in communication with, for example, a region (hereinafter simply referred to as a region) in which the heat transfer tubes 2a are provided on the wall surface of the heat recovery chamber 22. The combustion air supplied from the blower B12 may be supplied into the heat recovery chamber 22 via, for example, the region in which the heat transfer tubes 2a are provided on the wall surface of the heat recovery chamber 22.

[0028] In the following, the case where the combustion chamber 21 and the heat recovery chamber 22 are each located in a single housing (post-combustion furnace 2) will be described, but the present invention is not limited to this. Specifically, the combustion chamber 21 and the heat recovery chamber 22 may be located in separate housings (not shown), for example. In this case, the pyrolysis gas G1 discharged from the combustion chamber 21 may be supplied to the heat recovery chamber 22 via a pipe (not shown) that connects the housing in which the combustion chamber 21 is located and the housing in which the heat recovery chamber 22 is located.

[0029] The pump P (hereinafter also referred to as the supply device P) is, for example, a pump provided in either the pipe L41 or the pipe L42. The pipe L41 is, for example, a pipe that connects the inlet side of the heat medium H in the heat recovery chamber 22 (heat transfer tube 2a) with the outlet side of the heat medium H in the heat utilization facility 3. The pipe L42 is, for example, a pipe that connects the inlet side of the heat medium H in the heat utilization facility 3 with the outlet side of the heat medium H in the heat recovery chamber 22 (heat transfer tube 2a). The pump P circulates the heat medium H between the post-combustion furnace 2 and the heat utilization facility 3 via the pipes L41 and L42, for example, when a valve V21 provided in either the pipe L41 or the pipe L42 is open. Specifically, the pump P supplies the heat medium H, whose temperature has been increased in the heat recovery chamber 22 (heat transfer tube 2a), to the heat utilization facility 3. Furthermore, the pump P supplies the heat medium H cooled in the heat utilization facility 3 to the heat recovery chamber 22, for example.

[0030] The heat utilization facility 3 is, for example, a facility that utilizes thermal energy recovered in the post-combustion furnace 2 (heat recovery chamber 22).

[0031] Specifically, the heat utilization equipment 3 is, for example, a heat exchanger that uses the thermal energy of the heat medium H supplied by the pump P to heat the combustion air supplied from the blower B1 (combustion air supplied to the incinerator 1). The heat utilization equipment 3 is also, for example, a heat exchanger that uses the thermal energy of the heat medium H supplied by the pump P to keep the sludge warm in a digester tank (not shown), which is a facility upstream of the incinerator 1. The heat utilization equipment 3 is also, for example, a power generation system that generates power by using the thermal energy of the heat medium H supplied by the pump P. The heat utilization equipment 3 is also, for example, a drying system that dries sludge by using the thermal energy of the heat medium H supplied by the pump P.

[0032] As shown in FIG. 1, the incineration system 100 also includes, for example, a thermometer M1 that measures the combustion temperature in the post-combustion furnace 2 (combustion temperature of the pyrolysis gas G1).

[0033] Furthermore, the incineration system 100 has a control device 10 that controls the amount of combustion air supplied to the post-combustion furnace 2, for example, as shown in FIG.

[0034] The thermometer M1 is provided, for example, inside the heat recovery chamber 22 and measures the temperature inside the heat recovery chamber 22. Specifically, the thermometer M1 measures, for example, the temperature of the heat transfer tube 2a (hereinafter also referred to as the first temperature). More specifically, the thermometer M1 measures, for example, the temperature on the inner wall of the heat transfer tube 2a or the temperature on the outer wall of the heat transfer tube 2a. The following description will be given assuming that the thermometer M1 measures the temperature on the inner wall of the heat transfer tube 2a.

[0035] The control device 10 is, for example, an electronic device having an electronic circuit. Specifically, the control device 10 is, for example, one or more physical machines or one or more virtual machines having a CPU (Central Processing Unit) and a memory.

[0036] As shown in FIG. 2, the control device 10 controls the amount of heat medium H supplied by the pump P (hereinafter, also referred to as heat medium supply control), for example.

[0037] Specifically, the control device 10 acquires a first temperature (the temperature at the inner wall of the heat transfer tube 2a) measured by, for example, a thermometer M1. Then, based on, for example, the acquired first temperature, the control device 10 controls the pump P so that the heat medium H flows inside the heat transfer tube 2a at a flow rate that makes the first temperature equal to or lower than a predetermined temperature. The predetermined temperature is, for example, a predetermined temperature at which thermal degradation of the heat medium H does not occur. Note that the predetermined temperature may be, for example, the upper limit of the temperature at which thermal degradation of the heat medium H does not occur, or may be a temperature lower than the upper limit of the temperature at which thermal degradation of the heat medium H does not occur.

[0038] That is, the control device 10 in this embodiment continuously acquires, for example, the temperature (first temperature) of the heat transfer tube 2a as an index value of the boundary film temperature of the heat medium H. Then, by using, for example, the continuously acquired temperature (first temperature) of the heat transfer tube 2a, the control device 10 continuously controls (e.g., feedback control) the flow rate of the heat medium H flowing inside the heat transfer tube 2a so that the heat medium H flows inside the heat transfer tube 2a at a flow rate that can maintain the temperature of the heat transfer tube 2a at a temperature that does not cause thermal degradation of the heat medium H. In other words, the control device 10 dynamically changes the amount of heat medium H supplied by the pump P so that the heat medium H flows inside the heat transfer tube 2a at a flow rate that can keep the temperature of the heat transfer tube 2a within a range that does not cause thermal degradation.

[0039] As a result, the control device 10 in this embodiment can suppress, for example, the occurrence of thermal deterioration in the heat medium H flowing inside the heat transfer tube 2a.

[0040] Furthermore, the control device 10 in this embodiment dynamically controls the supply of the heat medium H based on, for example, the continuously acquired first temperature, thereby eliminating the need to constantly flow the heat medium H inside the heat transfer tube 2a at a sufficiently high flow rate (a flow rate that is sufficiently high enough to determine that thermal degradation of the heat medium H will not occur). Therefore, the control device 10 can, for example, reduce the amount of heat medium H supplied by the pump P, thereby reducing the load on the pump P and costs such as power consumption.

[0041] Furthermore, the control device 10 in this embodiment can, for example, dynamically control the supply of the heat medium H inside the heat transfer tube 2a, thereby adjusting the amount of heat medium H supplied by the pump P within a range that does not cause thermal degradation of the heat medium H. Therefore, the control device 10 can increase or decrease the amount of heat medium H supplied by the pump P depending on, for example, the amount of pyrolysis gas G1 supplied from the incinerator 1 to the post-combustion furnace 2 and the combustion temperature in the post-combustion furnace 2.

[0042] Specifically, for example, when the amount of pyrolysis gas G1 supplied from the incinerator 1 to the post-combustion furnace 2 is insufficient or when the combustion temperature in the post-combustion furnace 2 is insufficient, the control device 10 reduces the amount of heat transfer medium H supplied by the pump P within a range that does not cause thermal degradation of the heat transfer medium H, thereby making it possible to suppress the amount of thermal energy recovered in the post-combustion furnace 2. Therefore, even when the amount of pyrolysis gas G1 supplied from the incinerator 1 to the post-combustion furnace 2 is insufficient or when the combustion temperature in the post-combustion furnace 2 is insufficient, the control device 10 can maintain the combustion temperature of the pyrolysis gas G1 in the post-combustion furnace 2 and completely combust the pyrolysis gas G1.

[0043] [Control device 10 in the first embodiment] Next, the configuration of the control device 10 in the first embodiment will be described. Figure 3 is a diagram illustrating the hardware configuration of the control device 10.

[0044] 3, the control device 10 is a computer device having, for example, a CPU 101 which is a processor, a memory 102, a communication device 103, and a storage medium 104. Each unit is connected to each other via, for example, a bus 105.

[0045] The storage medium 104 has, for example, a program storage area (not shown) that stores a program 110 for controlling the supply of heat transfer medium. The storage medium 104 also has, for example, an information storage area 130 that stores information used when controlling the supply of heat transfer medium. The storage medium 104 may be, for example, a hard disk drive (HDD) or a solid state drive (SSD).

[0046] The CPU 101 controls the supply of the heating medium by executing a program 110 loaded into the memory 102 from the storage medium 104, for example.

[0047] The communication device 103 accesses, for example, via a network (not shown) such as the Internet, an operation terminal (not shown) through which the administrator of the incineration system 100 (hereinafter simply referred to as the administrator) inputs necessary information.

[0048] The control device 10 may include, for example, a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). The heat medium supply control may be performed by, for example, the FPGA or the ASIC.

[0049] In addition, the following description will be given assuming that the incineration system 100 has one control device 10, but this is not limiting. Specifically, the incineration system 100 may have, for example, multiple control devices 10. Heat medium supply control may be distributed among, for example, the multiple control devices 10.

[0050] [Heat medium supply control in the first embodiment] Next, the heat medium supply control in the first embodiment will be described. Fig. 4 is a flowchart illustrating the heat medium supply control in the first embodiment. Note that the following description will be given assuming that the valve V21 is open as an initial state. Also, the following description will be given assuming that the pump P is running and the heat medium H is circulating between the heat transfer tube 2a and the heat utilization equipment 3 as an initial state.

[0051] The control device 10 waits, for example, until a predetermined timing occurs. The predetermined timing may be a regular timing, for example, every minute.

[0052] Then, for example, at a predetermined timing, the control device 10 acquires the first temperature in the heat transfer tube 2a (step S101 in FIG. 4).

[0053] Specifically, the control device 10 acquires a first temperature measured by, for example, a thermometer M1. The measurement position of the first temperature by the thermometer M1 will be described below.

[0054] [First temperature measurement position] Fig. 5 is a diagram illustrating the measurement position of the first temperature. Specifically, Fig. 5 is a diagram illustrating a temperature change curve T0 that indicates the change in temperature inside and outside the heat transfer tube 2a.

[0055] As shown in Fig. 5, the heat transfer tube 2a is provided, for example, within a wall surface 2b of the post-combustion furnace 2 (heat recovery chamber 22), and is configured by a cylindrical side wall 2a1 at least a portion of which extends along the Y axis. As shown in Fig. 5, the heat transfer medium H flows, for example, from the Y2 direction side toward the Y1 direction side within at least a portion of the internal space 2a2 surrounded by the side wall 2a1. In the example shown in Fig. 5, the heat recovery chamber 22 (the combustion position of the pyrolysis gas G1) is located, for example, on the X1 direction side of the heat transfer tube 2a.

[0056] 5, the temperatures of the heat transfer tubes 2a and the wall surfaces 2b decrease, for example, from the X1 direction (the combustion position of the pyrolysis gas G1) toward the X2 direction. Therefore, the maximum temperature in the internal space 2a2 is usually a temperature T1 at a position 2a3 in the internal space 2a2 that is closest to the X1 direction.

[0057] Therefore, the thermometer M1 in this embodiment measures, for example, the temperature T1 at the position 2a3 as the first temperature. Then, as will be described later, the control device 10 in this embodiment controls the pump P so that the heat medium H flows inside the heat transfer tube 2a at a flow rate that can reduce the measured temperature T1 to a predetermined temperature or lower.

[0058] That is, the control device 10 in this embodiment controls the amount of heat medium H supplied by the pump P, for example, based on the temperature T1 at the position 2a3 where the temperature is highest in the internal space 2a2.

[0059] As a result, the control device 10 in this embodiment is able to control the heat medium H so that thermal degradation does not occur, even when the heat medium H flows through position 2a3 (near position 2a3) where the temperature is highest in the internal space 2a2.

[0060] Furthermore, although the thermometer M1 in this embodiment measures the temperature T1 at the position 2a3 as the first temperature, this is not limiting. For example, the thermometer M1 may measure the temperature T2 at the position 2a4 on the outer surface of the side wall 2a1, which is horizontal to the position 2a3 in the X-axis direction, as the first temperature. The temperature difference between the temperature T1 at the position 2a3 and the temperature T2 at the position 2a4 is small and can be calculated by thermal calculation or the like, so that it can be used as an indicator of the boundary film temperature of the heat medium H.

[0061] Returning to FIG. 4, the control device 10 controls the pump P, for example, based on the first temperature acquired in step S101, so that the heat medium H flows inside the heat transfer tube 2a at a flow rate that makes the first temperature equal to or lower than a predetermined temperature (step S102 in FIG. 4).

[0062] Specifically, the control device 10 controls the flow rate of the heat medium H in the internal space 2a2 by controlling, for example, the amount of the heat medium H that the pump P supplies to the heat transfer tube 2a (internal space 2a2).

[0063] More specifically, for example, when the control device 10 determines that the temperature difference between the first temperature acquired in step S101 and the predetermined temperature is equal to or less than a predetermined threshold, the control device 10 increases the flow rate of the heat medium H in the internal space 2a2 by increasing the amount of the heat medium H supplied to the heat transfer tube 2a (internal space 2a2) by the pump P. That is, in this case, the control device 10 performs control to lower the first temperature so that thermal degradation of the heat medium H does not occur.

[0064] Thus, the incineration system 100 of this embodiment includes, for example, a post-combustion furnace 2 that combusts pyrolysis gas G1 generated by the pyrolysis of the material to be incinerated. The post-combustion furnace 2 of this embodiment includes, for example, heat transfer tubes 2a that can recover thermal energy generated by the combustion of the pyrolysis gas G1 by flowing a heat transfer medium H therein. The incineration system 100 also includes, for example, a pump P that supplies the heat transfer medium H into the heat transfer tubes 2a, and a control device 10 that adjusts the flow rate of the heat transfer medium H within the heat transfer tubes 2a by controlling the pump P. The control device 10 of this embodiment acquires, for example, a first temperature of the heat transfer tube 2a, and, based on the acquired first temperature, controls the pump P so that the heat transfer medium H flows through the heat transfer tubes 2a at a flow rate that keeps the first temperature below a predetermined temperature.

[0065] That is, the control device 10 in this embodiment continuously controls (e.g., feedback control) the flow rate of the heat medium H flowing inside the heat transfer tube 2a by using, for example, the continuously acquired temperature (first temperature) of the heat transfer tube 2a so that the heat medium H flows inside the heat transfer tube 2a at a flow rate that can maintain the temperature of the heat transfer tube 2a at a temperature that does not cause thermal degradation of the heat medium H. In other words, the control device 10 dynamically changes the amount of heat medium H supplied by the pump P so that the heat medium H flows inside the heat transfer tube 2a at a flow rate that can keep the temperature of the heat medium H flowing inside the heat transfer tube 2a within a range that does not cause thermal degradation.

[0066] As a result, the control device 10 in this embodiment can suppress the occurrence of thermal deterioration in the heat medium H, for example.

[0067] Furthermore, the control device 10 in this embodiment dynamically controls the supply of the heat medium H based on the first temperature continuously acquired, for example, thereby not only suppressing the occurrence of thermal degradation in the heat medium H but also preventing the supply of an amount of the heat medium H greater than that required to suppress thermal degradation to the heat transfer tube 2a. Therefore, the control device 10 can suppress, for example, the load on the pump P and costs such as power consumption.

[0068] Furthermore, the control device 10 in this embodiment can, for example, dynamically control the supply of the heat medium H inside the heat transfer tube 2a, thereby adjusting the amount of heat medium H supplied by the pump P within a range that does not cause thermal degradation of the heat medium H. Therefore, the control device 10 can increase or decrease the amount of heat medium H supplied by the pump P depending on, for example, the amount of pyrolysis gas G1 supplied from the incinerator 1 to the post-combustion furnace 2 and the combustion temperature in the post-combustion furnace 2.

[0069] Specifically, for example, when the amount of pyrolysis gas G1 supplied from the incinerator 1 to the post-combustion furnace 2 is insufficient or when the combustion temperature in the post-combustion furnace 2 is insufficient, the control device 10 reduces the amount of heat transfer medium H supplied by the pump P within a range that does not cause thermal degradation of the heat transfer medium H, thereby making it possible to suppress the amount of thermal energy recovered in the post-combustion furnace 2. Therefore, even when the amount of pyrolysis gas G1 supplied from the incinerator 1 to the post-combustion furnace 2 is insufficient or when the combustion temperature in the post-combustion furnace 2 is insufficient, the control device 10 can maintain the combustion temperature of the pyrolysis gas G1 in the post-combustion furnace 2 and completely combust the pyrolysis gas G1.

[0070] On the other hand, for example, when the amount of pyrolysis gas G1 supplied from the incinerator 1 to the post-combustion furnace 2 is sufficient or the combustion temperature in the post-combustion furnace 2 is sufficient, the control device 10 increases the amount of heat transfer medium H supplied by the pump P within a range in which thermal degradation of the heat transfer medium H does not occur, thereby making it possible to completely combust the pyrolysis gas G1 while sufficiently recovering thermal energy.

[0071] In addition, in the incineration system 100 of this embodiment, for example, by controlling the flow rate of the heat medium H in the heat transfer tube 2a, the temperature rise of the heat medium H is suppressed, thereby eliminating the need to lower the temperature of the heat medium H by supplying cooling water, etc.

[0072] As a result, in the incineration system 100 of this embodiment, it is possible to suppress, for example, a decrease in the amount of recovered thermal energy due to a decrease in the temperature of the heat medium H. In addition, in the incineration system 100, for example, there is no need to have a supply device for supplying cooling water, etc., which makes it possible to suppress operating costs.

[0073] In the above example, the post-combustion furnace 2 has both the combustion chamber 21 and the heat recovery chamber 22, but this is not limiting. Specifically, the post-combustion furnace 2 in this embodiment may be, for example, a furnace that does not have the combustion chamber 21.

[0074] [Incineration system 100 in the second embodiment] Next, an incineration system 100 according to a second embodiment will be described. Figure 6 is a diagram illustrating an example of the configuration of the incineration system 100 according to the second embodiment.

[0075] As shown in Fig. 6, the control device 10 performs, for example, control of the amount of air sent from the blower B11 to the combustion chamber 21, control of the opening and closing of the valve V11 provided in the pipe L31, control of the amount of air sent from the blower B12 to the heat recovery chamber 22, and control of the opening and closing of the valve V12 provided in the pipe L32 (hereinafter, these controls will be collectively referred to as combustion control). Note that, hereinafter, the blower B11, the valve V11, and the pipe L31 will also be collectively referred to as a first supply unit 4. That is, the first supply unit 4 is a mechanism capable of supplying combustion air to, for example, the combustion chamber 21. Also, hereinafter, the blower B12, the valve V12, and the pipe L32 will also be collectively referred to as a second supply unit 5. That is, the second supply unit 5 is a mechanism capable of supplying combustion air to, for example, the heat recovery chamber 22.

[0076] Specifically, for example, when the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 is higher than a predetermined threshold value (hereinafter also referred to as the first threshold value), the control device 10 controls the first supply unit 4 and the second supply unit 5 so that the amount of combustion air supplied to the combustion chamber 21 is reduced and the amount of combustion air supplied to the heat recovery chamber 22 is increased.

[0077] That is, the case where the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 is equal to or higher than the first threshold value means, for example, that the amount of pyrolysis gas G1 supplied from the incinerator 1 to the post-combustion furnace 2 is sufficient, and that the combustion temperature of the pyrolysis gas G1 (combustion temperature in the heat recovery chamber 22) can be maintained at or above the temperature required for complete combustion of the pyrolysis gas G1 even when recovering thermal energy in the heat recovery chamber 22. Therefore, in this case, the control device 10 in this embodiment controls the combustion of the pyrolysis gas G1 to be more efficient in the heat recovery chamber 22 where thermal energy is recovered, for example, by decreasing the amount of combustion air supplied to the combustion chamber 21 and increasing the amount of combustion air supplied to the heat recovery chamber 22.

[0078] As a result, the control device 10 in this embodiment can fully recover thermal energy while completely combusting the pyrolysis gas G1, for example, when the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 is sufficient. Therefore, in this case, the control device 10 can fully recover thermal energy while preventing unburned components of the pyrolysis gas G1 from being discharged from the post-combustion furnace 2 to downstream equipment.

[0079] On the other hand, for example, when the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 is below a predetermined threshold value (hereinafter also referred to as the second threshold value) that is lower than the first threshold value, the control device 10 controls the first supply unit 4 and the second supply unit 5 so that the amount of combustion air supplied to the combustion chamber 21 increases and the amount of combustion air supplied to the heat recovery chamber 22 decreases.

[0080] That is, the case where the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 is lower than the second threshold value means, for example, that the amount of pyrolysis gas G1 supplied from the incinerator 1 to the post-combustion furnace 2 is insufficient, and recovery of thermal energy in the heat recovery chamber 22 may make it impossible to maintain the combustion temperature of the pyrolysis gas G1 (combustion temperature in the heat recovery chamber 22) at or above the temperature required for complete combustion of the pyrolysis gas G1. Therefore, in this case, the control device 10 in this embodiment controls, for example, by increasing the amount of combustion air supplied to the combustion chamber 21 while decreasing the amount of combustion air supplied to the heat recovery chamber 22, so that more combustion of the pyrolysis gas G1 is performed in the combustion chamber 21 where thermal energy is not recovered.

[0081] As a result, the control device 10 in this embodiment can completely combust the pyrolysis gas G1 even when, for example, the combustion temperature of the pyrolysis gas G1 is insufficient in the heat recovery chamber 22. Therefore, even in this case, the control device 10 can prevent, for example, unburned pyrolysis gas G1 from being discharged from the post-combustion furnace 2 to downstream equipment.

[0082] For example, when adjusting the amount of combustion air supplied to the combustion chamber 21 and the amount of combustion air supplied to the heat recovery chamber 22, the control device 10 may make adjustments so that the sum of the amount of combustion air supplied to the combustion chamber 21 and the amount of combustion air supplied to the heat recovery chamber 22 remains constant.

[0083] [Combustion control in the second embodiment] Next, combustion control in the second embodiment will be described. Fig. 7 is a flowchart illustrating combustion control in the second embodiment. Note that the following description will be given assuming that the valves V11 and V12 are open as an initial state. Also, the following description will be given assuming that the blowers B11 and B12 are activated and that the supply of combustion air from blower B11 to the combustion chamber 21 and the supply of combustion air from blower B12 to the heat recovery chamber 22 have started as an initial state.

[0084] The control device 10 waits, for example, until a first timing occurs. The first timing may be a regular timing, for example, every minute.

[0085] Then, for example, when the first timing arrives, the control device 10 determines whether or not the combustion state in the post-combustion furnace 2 (heat recovery chamber 22) satisfies a predetermined condition (hereinafter also referred to as the first condition) as shown in Fig. 7 (step S11 in Fig. 7). The first condition is, for example, that the combustion temperature in the heat recovery chamber 22 is equal to or higher than a first threshold value, or that the combustion temperature in the heat recovery chamber 22 is lower than a second threshold value.

[0086] Specifically, the control device 10 acquires the combustion temperature (combustion temperature inside the heat recovery chamber 22) measured by, for example, the thermometer M1, and determines whether the acquired combustion temperature satisfies the first condition.

[0087] As a result, if it is determined in step S11 that the combustion state in the post-combustion furnace 2 satisfies the first condition (YES in step S12 in FIG. 7), the control device 10 controls, for example, the first supply unit 4 and the second supply unit 5 (step S13 in FIG. 7).

[0088] Specifically, for example, when the control device 10 determines that the combustion temperature measured by the thermometer M1 is equal to or higher than a first threshold value, it controls the first supply unit 4 and the second supply unit 5 so as to reduce the amount of combustion air supplied to the combustion chamber 21 and increase the amount of combustion air supplied to the heat recovery chamber 22.

[0089] More specifically, in this case, the control device 10 performs control to reduce the frequency of an inverter (not shown) attached to the motor (not shown) of the blower B11 or control to reduce the opening of the valve V11 so that the amount of combustion air blown from the blower B11 to the combustion chamber 21 decreases, and also performs control to increase the frequency of an inverter attached to the motor of the blower B12 or control to increase the opening of the valve V12 so that the amount of combustion air blown from the blower B12 to the heat recovery chamber 22 increases.

[0090] In other words, in this case, the control device 10 not only completely combusts the pyrolysis gas G1 but also controls the amount of recovered thermal energy to be increased by, for example, controlling the combustion of the pyrolysis gas G1 to be more effective in the heat recovery chamber 22 where the thermal energy is recovered.

[0091] For example, when blower B11 and blower B12 are a single blower, the control device 10 may control the valve V11 to reduce the opening so that the amount of combustion air blown from the blower to the combustion chamber 21 decreases, and may control the valve V12 to increase the opening so that the amount of combustion air blown from the blower to the heat recovery chamber 22 increases.

[0092] In addition, for example, when the control device 10 determines that the combustion temperature measured by the thermometer M1 is less than the second threshold value, it controls the first supply unit 4 and the second supply unit 5 so that the amount of combustion air supplied to the combustion chamber 21 increases and the amount of combustion air supplied to the heat recovery chamber 22 decreases.

[0093] More specifically, in this case, the control device 10 performs control to increase the frequency of the inverter attached to the motor of the blower B11 or control to increase the opening of the valve V11 so as to increase the amount of combustion air blown from the blower B11 to the combustion chamber 21, and also performs control to decrease the frequency of the inverter attached to the motor of the blower B12 or control to decrease the opening of the valve V12 so as to decrease the amount of combustion air blown from the blower B12 to the heat recovery chamber 22.

[0094] In other words, in this case, the control device 10 controls the amount of thermal energy recovered by, for example, controlling the combustion of the pyrolysis gas G1 to be more intense in the combustion chamber 21 where thermal energy recovery is not performed, thereby controlling the amount of thermal energy recovered so that complete combustion of the pyrolysis gas G1 continues.

[0095] For example, when blower B11 and blower B12 are a single blower, the control device 10 may control the valve V11 to increase the opening so as to increase the amount of combustion air blown from the blower to the combustion chamber 21, and may control the valve V12 to decrease the opening so as to decrease the amount of combustion air blown from the blower to the heat recovery chamber 22.

[0096] Returning to FIG. 7, if it is determined in step S11 that the combustion state in the post-combustion furnace 2 does not satisfy the first condition (NO in step S12 in FIG. 7), the control device 10 may not perform step S13, for example.

[0097] For example, when it is determined that the combustion temperature measured by the thermometer M1 is equal to or higher than the first threshold, the control device 10 may control the first supply unit 4 and the second supply unit 5 so that all of the amount of combustion air capable of combusting the pyrolysis gas G1 supplied from the incinerator 1 to the post-combustion furnace 2 is supplied from the second supply unit 5. Specifically, in this case, the control device 10 may control the first supply unit 4 and the second supply unit 5 so that combustion air is supplied only from the second supply unit 5 out of the first supply unit 4 and the second supply unit 5.

[0098] That is, in this case, the control device 10 may perform control so that the combustion of the pyrolysis gas G1 is carried out in the heat recovery chamber 22 as much as possible, for example.

[0099] Furthermore, for example, when it is determined that the combustion temperature measured by the thermometer M1 is lower than the second threshold value, the control device 10 may control the first supply unit 4 and the second supply unit 5 so that all of the amount of combustion air capable of combusting the pyrolysis gas G1 supplied from the incinerator 1 to the post-combustion furnace 2 is supplied from the first supply unit 4. Specifically, in this case, the control device 10 may control the first supply unit 4 and the second supply unit 5 so that, for example, combustion air is supplied from only the first supply unit 4 out of the first supply unit 4 and the second supply unit 5.

[0100] That is, in this case, the control device 10 may perform control so that the combustion of the pyrolysis gas G1 occurs in the combustion chamber 21 as much as possible, for example.

[0101] [Specific example of combustion control in the second embodiment] Next, a specific example of combustion control in the second embodiment will be described below. Figures 8 and 9 are diagrams for explaining a specific example of combustion control in the second embodiment.

[0102] For example, when the combustion temperature in the heat recovery chamber 22 (combustion temperature measured by thermometer M1) is equal to or higher than a first threshold value, the control device 10 controls the first supply unit 4 and the second supply unit 5 so that the amount of combustion air supplied to the combustion chamber 21 from line L31 is reduced and the amount of combustion air supplied to the heat recovery chamber 22 from line L32 is increased.

[0103] As a result, the control device 10 can generate a high-temperature field HT1 suitable for burning the pyrolysis gas G1 within the heat recovery chamber 22, as shown in Figure 8, thereby enabling the pyrolysis gas G1 to be completely combusted within the heat recovery chamber 22 and also enabling sufficient recovery of thermal energy.

[0104] In addition, for example, when the combustion temperature in the heat recovery chamber 22 (combustion temperature measured by the thermometer M1) is less than the second threshold value, the control device 10 controls the first supply unit 4 and the second supply unit 5 so that the amount of combustion air supplied to the combustion chamber 21 from the line L31 increases and the amount of combustion air supplied to the heat recovery chamber 22 from the line L32 decreases.

[0105] This enables the control device 10 to generate a high-temperature field HT2 suitable for burning the pyrolysis gas G1 within the combustion chamber 21, as shown in Figure 9, and to completely combust the pyrolysis gas G1 within the thermal combustion chamber 21.

[0106] Thus, the incineration system 100 of this embodiment includes, for example, a combustion chamber 21 that combusts pyrolysis gas G1 generated by the pyrolysis of the material to be incinerated, and a heat recovery chamber 22 that combusts the pyrolysis gas G1 and recovers the thermal energy generated by the combustion of the pyrolysis gas G1. The incineration system 100 also includes, for example, a first supply unit 4 that can supply combustion air to the combustion chamber 21. The incineration system 100 also includes, for example, a second supply unit 5 that can supply combustion air to the heat recovery chamber 22.

[0107] Specifically, in the incineration system 100 of this embodiment, the heat recovery chamber 22 has, for example, heat transfer tubes 2a provided along the wall surface of the heat recovery chamber 22. Furthermore, the second supply unit 5 supplies combustion air into the heat recovery chamber 22, for example, from the area on the wall surface of the heat recovery chamber 22 where the heat transfer tubes 2a are provided. This makes it possible to recover thermal energy while completely combusting the material to be incinerated. Furthermore, the heat transfer tubes 2a are formed, for example, continuously in the area on the wall surface of the heat recovery chamber 22 where the heat transfer tubes 2a are provided.

[0108] The incineration system 100 in this embodiment also has a control device 10 that controls the first supply unit 4 and the second supply unit 5 in accordance with the combustion state of the pyrolysis gas G1 in the heat recovery chamber 22, for example.

[0109] Specifically, for example, when the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 is equal to or higher than a first threshold, the control device 10 controls the first supply unit 4 and the second supply unit 5 to increase the amount of combustion air supplied by the second supply unit 5. Furthermore, for example, when the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 is lower than a second threshold, the control device 10 controls the first supply unit 4 and the second supply unit 5 to increase the amount of combustion air supplied by the first supply unit 4.

[0110] That is, for example, when the material to be incinerated is sludge, the amount of pyrolysis gas G1 supplied from the incinerator 1 decreases depending on the amount and properties of the sludge supplied to a sewage treatment facility (not shown), which is a facility upstream of the incinerator 1. If the amount of pyrolysis gas G1 supplied from the incinerator 1 decreases, the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 in the post-combustion furnace 2 may decrease, preventing complete combustion of the pyrolysis gas G1.

[0111] In this regard, for example, if the manager detects a decrease in the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22, the manager can suppress the decrease in the combustion temperature in the post-combustion furnace 2 (heat recovery chamber 22) by injecting auxiliary fuel (not shown) into the post-combustion furnace 2, thereby enabling the complete combustion of the pyrolysis gas G1 in the post-combustion furnace 2 to continue.

[0112] However, in this case, the incineration system 100 may require, for example, the purchase of auxiliary fuel, which may increase operating costs.

[0113] Therefore, the control device 10 in this embodiment fluidly changes the combustion position of the pyrolysis gas G1 in the post-combustion furnace 2 according to the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22, thereby maintaining complete combustion of the pyrolysis gas G1 even when the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 changes. Specifically, when the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 is insufficient, for example, the control device 10 changes the combustion location of the pyrolysis gas G1 from the heat recovery chamber 22, where thermal energy is recovered, to the combustion chamber 21, where thermal energy is not recovered, thereby suppressing the amount of recovered thermal energy and maintaining complete combustion of the pyrolysis gas G1.

[0114] As a result, the control device 10 in this embodiment can continue complete combustion of the pyrolysis gas G1 even when, for example, the combustion temperature of the pyrolysis gas G1 is insufficient in the heat recovery chamber 22. Therefore, even in this case, the control device 10 can prevent, for example, unburned pyrolysis gas G1 from being discharged from the post-combustion furnace 2 to downstream equipment.

[0115] On the other hand, for example, when the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 is sufficient, the control device 10 in this embodiment not only performs complete combustion of the pyrolysis gas G1 but also increases the amount of recovered thermal energy. Therefore, in this case, the control device 10 can, for example, prevent unburned pyrolysis gas G1 from being discharged from the post-combustion furnace 2 to downstream equipment while also sufficiently recovering thermal energy.

[0116] In addition, the control device 10 in this embodiment may, for example, increase the amount of combustion air supplied by the first supply unit 4 and decrease the amount of combustion air supplied by the second supply unit 5 when the combustion temperature of the pyrolysis gas G1 in the heat recovery chamber 22 is below a first threshold value.

[0117] Furthermore, the combustion control in this embodiment allows for a larger range of increase / decrease (control range) in the amount of recovered thermal energy than, for example, the heating medium supply control in Embodiment 1. Therefore, the control device 10 in this embodiment may perform the combustion control in this embodiment instead of or in addition to the heating medium supply control in the first embodiment when, for example, the heating medium supply control in the first embodiment does not allow complete combustion of the pyrolysis gas G1.

[0118] Furthermore, the control device 10 in this embodiment may be, for example, the same device as the control device 10 in the first embodiment, or may be a device different from the control device 10 in the first embodiment. [Explanation of symbols]

[0119] 1: Incinerator 2: Post-combustion furnace 2a: Heat transfer tube 2a1: Side wall 2a2:Inner space 2a3:Position 2a4:Position 2b:Wall surface 3: Heat utilization equipment 4: 1st supply section 5: Second supply unit 10: Control device 21: Combustion chamber 22: Heat recovery chamber 100: Incineration system 101: CPU 102: Memory 103: Communication device 104: Storage medium 105: Bus 110: Program 130: Information storage area B1: Blower B11: Blower B12: Blower G1: Pyrolysis gas G2: Exhaust gas H: Heat transfer medium L1: Piping L2: Piping L11: Piping L21: Piping L31: Piping L32: Piping L41: Piping L42: Piping M1: Thermometer P: Pump T0: Temperature change curve T1: Temperature T2: Temperature V11: Valve V12: Valve V21: Valve

Claims

1. Equipped with a post-combustion furnace that burns gas generated by the thermal decomposition of the incineration material, the post-combustion furnace has a heat transfer tube capable of recovering thermal energy generated by the combustion of the gas by flowing a heat medium therein; a supply device that supplies the heat medium into the heat transfer tube; a control device that controls the supply device to adjust the flow rate of the heat medium in the heat transfer tube, The control device obtaining a first temperature of the heat transfer tube; an incineration system that controls the supply device based on the acquired first temperature so that the heat medium flows inside the heat transfer tube at a flow rate that makes the first temperature equal to or lower than a predetermined temperature.

2. Equipped with a post-combustion furnace that burns gas generated by the thermal decomposition of the incineration material, the post-combustion furnace has a heat transfer tube capable of recovering thermal energy generated by the combustion of the gas by flowing a heat medium therein; Furthermore, a heat transfer medium supply control method in an incineration system having a supply device that supplies the heat transfer medium into the heat transfer tube, obtaining a first temperature of the heat transfer tube; a heat medium supply control method for controlling the supply device based on the acquired first temperature so that the heat medium flows inside the heat transfer tube at a flow rate that makes the first temperature equal to or lower than a predetermined temperature.

Images