JP2012163306A - Burner device and industrial furnace with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve highly efficient heating of combustion air by a burner device through the use of a chemical heat pump.SOLUTION: A burner device 1 includes a burner 3, a recuperator 4 that uses heat recovered from combustion exhaust gas from the burner 3 to preheat combustion air supplied to the burner 3, and a chemical heat pump 5 that absorbs heat from the combustion exhaust gas having been supplied to the recuperator 4 and releases absorbed heat to combustion air before it is supplied to the burner 3. The chemical heat pump 5 repeats a cycle of a heat accumulation mode, standby mode, and heat dissipation mode.

Description

  The present invention relates to a burner apparatus and an industrial furnace (including various metal heating furnaces) provided with the burner apparatus.

  In industrial furnaces, combustion exhaust gas generated from burners has been recovered in a heat exchange device such as a recuperator or regenerative burner, and heat efficiency has been improved by preheating the air required for combustion (for example, recuperators). (See Patent Document 1 for Regenerative Burner, and Patent Document 2 for Regenerative Burner).

  However, in the case of a recuperator, the exhaust gas temperature after heat exchange is about 400 ° C. and the preheated air temperature is about 500 ° C., and sufficient heat recovery is not performed, and further heat recovery is desired.

  In the regenerative burner, the exhaust gas temperature after heat exchange is about 200 ° C. and the temperature of the preheated air is about 1000 ° C., and the heat recovery is improved as compared with the recuperator. If it can be recovered, further energy saving will be possible. Also, at present, the amount of exhaust gas required for heat exchange is about 80% of the total, and the remaining about 20% is discarded at about 800 ° C. after heat exchange with the heated object in the furnace and is not effectively used. .

  On the other hand, a chemical heat pump that stores and absorbs heat using a chemical reaction that involves endothermic or exothermic reactions is known (see, for example, Patent Document 3). As its name suggests, this chemical heat pump can output a temperature higher than the input. For example, the system shown by the following reaction formula using calcium oxide, water, and calcium hydroxide is mentioned.

In this system, the reaction proceeds to the left by applying heat to Ca (OH) ₂ , CaO and H ₂ O (water vapor) are obtained, and the reverse reaction is suppressed by condensing the water vapor and separating it as water. it can. After the reaction in the left direction is completed, the water separated and condensed in the obtained CaO is evaporated and supplied as water vapor, whereby the reaction proceeds to the right, and the amount of heat Q _H can be obtained.

Japanese Patent No. 3828968 Japanese Patent Publication No. 7-26730 JP-A-1-49860

  An object of the present invention is to realize high-efficiency heating of combustion air by using a chemical heat pump for heat recovery from combustion exhaust gas and heating of combustion air in a burner apparatus.

  According to a first aspect of the present invention, there is provided a burner, a main heat exchange unit for preheating combustion air supplied to the burner with heat recovered from combustion exhaust gas of the burner, and before being supplied to the main heat exchange unit or There is provided a burner device comprising a chemical heat pump that absorbs heat from the later combustion exhaust gas and releases the absorbed heat to the combustion air before being supplied to the burner.

  The burner device of the present invention can heat combustion air with high efficiency by including a chemical heat pump in addition to the main heat exchange section. In particular, by providing a chemical heat pump, the combustion air can be heated to a temperature higher than the temperature of the combustion exhaust gas. In addition, by providing a chemical heat pump, it is possible to recover the combustion exhaust gas after being supplied to the main heat exchange section, that is, heat from a low-temperature heat source and use it for heating the combustion air.

  For example, the main heat exchange unit is a recuperator. Combining a recuperator with a chemical heat pump can reduce fuel consumption by increasing the temperature of combustion air. Moreover, even if combustion exhaust gas is 800 degrees C or less, since combustion air can be preheated to 800 degrees C or more, high temperature air combustion suitable for energy saving is realizable.

  Alternatively, the main heat exchanging part is a heat storage body of a regenerative burner.

  By combining a regenerative burner with a chemical heat pump to improve the heating efficiency of combustion air, especially when newly installing a burner device, the heat storage body can be reduced in size, and the exhaust gas suction rate (heating of the heat storage body relative to the entire combustion exhaust gas) The ratio of the combustion exhaust gas used in the process can also be reduced. As a result, the capacity of the exhaust gas suction fan can be reduced. Moreover, the amount of high-temperature exhaust gas discharged without being used for heating the heat storage body is increased, and for example, the amount of heat recovered by a waste heat recovery boiler can be increased.

  Regardless of whether the burner apparatus is newly installed or existing, the burner switching time is extended by combining the regenerative burner with a chemical heat pump to improve the heating efficiency of the combustion air. As a result, the life of the device for switching the burner, such as a switching valve, can be extended. By extending the burner switching time, fluctuations in temperature and pressure generated in the furnace when the burner is switched can be suppressed, and the uniformity in the furnace is also improved.

  In the case of existing burner devices, the exhaust gas suction fan can be reduced by improving the heating efficiency of combustion air by combining a regenerative burner with a chemical heat pump to improve the heating efficiency of combustion air. The capacity can be reduced and the amount of high-temperature exhaust gas can be increased.

  Specifically, the chemical heat pump contains a chemical heat storage material, and a reaction unit provided with a heat exchanger for heat exchange between the chemical heat storage material and the combustion exhaust gas and the combustion air, In the reaction part, the product generated when the chemical heat storage material absorbs heat from the combustion exhaust gas is taken out from the reaction part and condensed, and when the chemical heat storage material releases heat to the combustion air in the reaction part, A condensing and evaporating unit that evaporates and feeds the reaction unit.

  More specifically, the chemical heat pump includes three reaction units, and each of the reaction units includes a heat storage mode in which the chemical heat storage material absorbs heat from the combustion exhaust gas, the chemical heat storage material, the combustion exhaust gas, and The standby mode in which heat exchange with the combustion air is not performed, and the heat release mode in which the chemical heat storage material dissipates heat to the combustion air are repeated, and the heat storage mode, the standby mode, And the period which repeats heat dissipation mode has shifted mutually.

  With this configuration, it is possible to stably heat the combustion air by suppressing temporal fluctuations in the heating efficiency of the combustion air by the chemical heat pump.

  Preferably, the start timing of the heat release mode in the next reaction section comes before the end timing of the heat release mode of each of the reaction sections. If it does in this way, the temporal change of the heating efficiency of the combustion air by a chemical heat pump can be suppressed more effectively by providing temporal overlap between the heat dissipation modes performed in order by three reaction parts. Here, for convenience, the number of reaction units is three, but it goes without saying that three or more reaction units may be provided as long as the same operation is possible.

  A second aspect of the present invention provides an industrial furnace provided with the burner device.

  The burner device of the present invention includes a chemical heat pump in addition to the main heat exchange part (recuperator and regenerative burner) for recovering heat from the combustion exhaust gas and preheating the combustion air by the recovered heat. Heat can also be recovered from the combustion exhaust gas (that is, a low-temperature heat source) after being supplied to the exchange unit to heat the combustion air with high efficiency, and the combustion air can be heated to a temperature higher than the temperature of the combustion exhaust gas.

The schematic diagram which shows the furnace provided with the burner apparatus of 1st Embodiment of this invention. The block diagram which shows the burner apparatus of 1st Embodiment of this invention. The block diagram which shows the structure at the time of paying attention to only one reactor. The conceptual diagram for demonstrating the operation mode of a reactor. The conceptual diagram for demonstrating the alternative of the operation mode of a reactor. The typical time chart for demonstrating switching of the operation mode of a reactor. The typical time chart for demonstrating the opening-and-closing state of the valve in each operation mode. The block diagram which shows the driving | running state of the burner apparatus of 1st Embodiment of this invention. The block diagram which shows the driving | running state of the burner apparatus of 1st Embodiment of this invention. The block diagram which shows the driving | running state of the burner apparatus of 1st Embodiment of this invention. The schematic diagram which shows the furnace provided with the burner apparatus of 2nd Embodiment of this invention. The block diagram which shows the burner apparatus of 2nd Embodiment of this invention. The block diagram which shows the driving | running state of the burner apparatus of 2nd Embodiment of this invention. The block diagram which shows the driving | running state of the burner apparatus of 2nd Embodiment of this invention. The block diagram which shows the driving | running state of the burner apparatus of 2nd Embodiment of this invention. The block diagram which shows the burner apparatus of the modification of this invention. The block diagram which shows the burner apparatus of the other modification of this invention.

  Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 schematically shows an industrial furnace 2 provided with a burner device 1 according to a first embodiment of the present invention. The burner device 1 includes a burner 3, a recuperator (main heat exchange unit) 4, and a chemical heat pump 5. The burner 3 attached to the furnace wall of the industrial furnace 2 injects fuel into the furnace together with the combustion air sent from the combustion air fan 8 through the air line 7 and burns it in the furnace. A recuperator 4 is provided in an exhaust gas line 9 for discharging combustion exhaust gas to the outside of the furnace. In the recuperator 4, heat exchange is performed between the combustion exhaust gas discharged through the exhaust gas line 9 and the combustion air sent to the burner 3 through the air line 7, and the combustion air is heated (primary heat exchange). ). The air line 7 passes through the chemical heat pump 5. The combustion air heat-exchanged with the combustion exhaust gas in the recuperator 4 is further heated (secondary heat exchange) by exchanging heat with a chemical heat storage material 14 described later in the chemical heat pump 5.

  2 and 3, the chemical heat pump 5 includes three reactors (reaction units) A, B, and C, a condenser 11, a cold heat source 12, and an evaporator 13.

  In each of the reactors A to C, calcium hydroxide is accommodated as the chemical heat storage material 14. Moreover, the 1st heat exchanger 15 is arrange | positioned in each reactor A-C.

  The aforementioned air line 7 includes an upstream air line 7a and a downstream air line 7b. The upstream air line 7a is connected to the combustion air fan 8 on the upstream side, and connected to the inlet of the first heat exchanger 15 of each of the reactors A to C via the air inlet valve 16a on the downstream side. On the other hand, the downstream air line 7b is connected to the outlet of the first heat exchanger 15 of each of the reactors A to C via the air outlet valve 16b, and the downstream side is connected to the burner 3.

  In the exhaust gas line 9, a detour line 17 is provided that branches from the exhaust gas line 9 on the downstream side of the recuperator 4 and merges with the exhaust gas line 9 again through the chemical heat pump 5. The detour line 17 includes an upstream detour line 17a and a downstream detour line 17b. The upstream detour line 17a is connected to the exhaust gas line 9 on the upstream side, and connected to the inlet of the first heat exchanger 15 of each of the reactors A to C via the exhaust gas inlet valve 18a on the downstream side. On the other hand, the downstream bypass line 17 b is connected to the outlet of the first heat exchanger 15 of each of the reactors A to C via the exhaust gas outlet valve 18 b on the upstream side, and connected to the exhaust gas line 9 on the downstream side. A second heat exchanger 19 of the evaporator 13 is interposed in the downstream bypass line 17b.

  A steam extraction line 21 that connects the reactors A to C and the condenser 11 is provided. The steam extraction line 21 has an upstream side connected to the individual reactors A to C via a steam outlet valve 22 b and a downstream side connected to the condenser 11.

  A steam supply line 23 connecting the reactors A to C and the evaporator 13 is provided. The steam supply line 23 has an upstream side connected to the evaporator 13 and a downstream side connected to individual reaction vessels A to C via a steam inlet valve 22a.

  The condenser 11 and the evaporator 13 are connected by a condensed water supply line 25 provided with a normally open partition valve 24.

  The controller 27 controls combustion in the furnace by the burner 3, the combustion air fan 8, and a fuel supply device (not shown), and the chemical heat pump 5 is opened and closed by opening and closing valves 16a, 16b, 18a, 18b, 22a, 22b, and 24. Control.

  As conceptually shown in FIG. 4A, in the present embodiment, the three reactors A to C included in the chemical heat pump 5 each repeat the heat storage mode, the standby mode, and the heat release mode in this order. Further, as conceptually shown in FIG. 5, the cycles in which the heat storage mode, the standby mode, and the heat release mode are repeated among the three reactors A to C are shifted from each other. First, when the reactor A is in the heat storage mode, the reactor B is in the heat release mode and the reactor C is in the standby mode. Further, when the reactor A is in the standby mode, the reactor B is in the heat storage mode and the reactor C is in the heat release mode. Further, when the reactor A is in the heat release mode, the reactor B is in the standby mode and the reactor C is in the heat storage mode. As shown in FIG. 6, the heat storage mode, standby mode, and heat release mode in each of the reactors A to C are the air inlet valve 16a, the air outlet valve 16b, the exhaust gas inlet valve 18a, the exhaust gas outlet valve 18b, and the steam inlet valve 22a. And the controller 27 controls the opening and closing of the steam outlet valve 22b. As conceptually shown in FIG. 4B, the individual reactors A to C may repeat the modes in the reverse order of the present embodiment, that is, the heat storage mode, the heat release mode, and the standby mode.

  Hereinafter, the heat storage mode, the standby mode, and the heat release mode will be specifically described mainly focusing on the reactor A. In FIGS. 7A to 7C, the opened valve is shown in black, and the closed valve is shown in white.

  First, the heat storage mode will be described. In the heat storage mode, the chemical heat storage material 14 of the reactors A to C absorbs heat from the combustion exhaust gas and accumulates it. As shown in FIG. 7A, when the reactor A is in the heat storage mode, the air inlet valve 16a and the air outlet valve 16b of the reactor A are closed, and the exhaust gas inlet valve 18a and the exhaust gas outlet valve 18b are opened. Further, when the reactor A is in the heat storage mode, the steam inlet valve 22a of the reactor A is closed and the steam outlet valve 22b is opened.

  When the reactor A is in the heat storage mode, a part of the combustion exhaust gas after passing through the recuperator 4 passes from the exhaust gas line 9 through the upstream bypass line 17a and the opened exhaust gas inlet valve 18a. It is supplied to the inlet of the heat exchanger 15 and passes through the first heat exchanger 15. Further, the combustion exhaust gas flows into the downstream detour line 17b via the exhaust gas outlet valve 18b opened from the outlet of the first heat exchanger 15 of the reactor A, and the second heat exchanger 19 of the evaporator 13 is passed through the exhaust gas outlet valve 18b. Return to the exhaust gas line 9.

In the reactor A in the heat storage mode, the heat (heat quantity Q _H ) of the combustion exhaust gas is absorbed by the chemical heat storage material 14 by the leftward chemical reaction in the following formula (1) in the first heat exchanger 15. In other words, occurs endothermic reaction by heat Q _H of the combustion exhaust gas is added to the calcium hydroxide, water vapor is generated together with calcium hydroxide is calcium oxide.

The steam generated in the reactor A by the endothermic reaction is supplied to the condenser 11 through the steam outlet valve 22b and the steam extraction line 21 which are opened. In the condenser 11, the water vapor is condensed by heat exchange with the cold heat source 12 (for example, cooling water) to become water, and the condensation heat Q _L is released. Water in the condenser 11 is supplied to the evaporator 13 through a condensed water supply line 25 and a gate valve 24 that is open.

As described above, the combustion exhaust gas flowing into the lower bypass line 17 b from the first heat exchanger 15 of the reactor A passes through the second heat exchanger 19 of the evaporator 13 before returning to the exhaust gas line 9. Heat exchange is performed between the combustion exhaust gas passing through the second heat exchanger 19 and the water in the evaporator 13 (water condensed in the condenser 11). By this heat exchange, the water in the evaporator 13 absorbs the evaporation heat Q _L from the combustion exhaust gas and evaporates to become water vapor. The water vapor generated in the evaporator 13 is supplied via the vapor supply line 23 to the reactor B in the heat release mode when the reactor A is in the heat storage mode.

  Next, the standby mode will be described. In the standby mode, the chemical heat storage material 14 of the reactors A to C does not exchange heat with either the combustion exhaust gas or the combustion air. As shown in FIG. 7B, when the reactor A is in the standby mode, the air inlet valve 16a, the air outlet valve 16b, the exhaust gas inlet valve 18a, the exhaust gas outlet valve 18b, the steam inlet valve 22a, and the steam outlet valve 22b are all closed. Has been. That is, the reactor A in the standby mode is disconnected from any of the burner 3, the air line 7, the exhaust gas line 9, the condenser 11, and the evaporator 13.

  Next, the heat dissipation mode will be described. In the heat dissipation mode, the chemical heat storage material 14 of the reactors A to C releases the heat accumulated in the heat storage mode to heat the combustion air. As shown in FIG. 7C, when the reactor A is in the heat release mode, the air inlet valve 16a and the air outlet valve 16b of the reactor A are opened, and the exhaust gas inlet valve 18a and the exhaust gas outlet valve 18b are closed. Further, when the reactor A is in the heat release mode, the steam inlet valve 22a of the reactor A is opened, and the steam outlet valve 22b is closed.

When the reactor A is in the heat release mode, water vapor generated in the evaporator 13 (generated by heat exchange with the combustion exhaust gas supplied from the reactor C in the heat storage mode to the second heat exchanger 19). It is supplied into the reaction vessel A through the steam supply line 23 and the opened steam inlet valve 22a. In the reactor A to which water vapor (H ₂ O) is supplied, the chemical heat storage material 14 releases the heat Q _H stored in the previous heat storage mode by the rightward chemical reaction in the above-described equation (1). That is, when water is added to calcium oxide, an exothermic reaction occurs, and heat Q _H is generated along with the formation of calcium hydroxide.

When the reactor A is in the heat release mode, the combustion air that has passed through the recuperator 4 enters the inlet of the first heat exchanger 15 of the reactor A via the upstream air line 7a and the opened air inlet valve 16a. Supplied and passes through the first heat exchanger 15. Since the reactor the chemical heat storage material 14 in A as described above is discharged heat Q _H, combustion air passing through the first heat exchanger 15 is heated by heat exchange with the chemical heat storage material 14.

  The burner device 1 of this embodiment has the following characteristics.

  Combining the recuperator 4 with the chemical heat pump 5 can heat the combustion air with high efficiency. Heating with high efficiency can increase the temperature of combustion air and reduce fuel consumption. Moreover, by providing the chemical heat pump 5, the combustion air can be heated to a temperature higher than the temperature of the combustion exhaust gas. For example, even if the combustion exhaust gas is 800 ° C. or lower, the combustion air can be preheated to 800 ° C. or higher, and high-temperature air combustion suitable for energy saving can be realized. Further, by providing the chemical heat pump 5, the combustion exhaust gas after being supplied to the recuperator 4, that is, heat recovery from a low-temperature heat source can be performed and used for heating the combustion air. However, the combustion exhaust gas may be supplied to the heat storage mode reactor among the reactors A to C of the chemical heat pump 5 before passing through the recuperator 4 and then supplied to the recuperator 4.

  As shown in FIG. 5, the three reactors A to C sequentially repeat the heat storage mode, the standby mode, and the heat release mode, and the cycles of repeating these modes among the reactors A to C are shifted from each other. Therefore, any of the three reactors A to C is always in the heat release mode and heats the combustion air. Therefore, temporal fluctuation of the heating efficiency of the combustion air by the chemical heat pump 5 can be suppressed, and the combustion air can be stably heated.

  In addition, as shown with the code | symbol t in FIG. 5, before the completion | finish timing Te of the heat dissipation mode of any of reactors A-C, it will be in the heat dissipation mode next of reactors A-C ( For example, when the reactor A is in the heat dissipation mode, it is preferable that the start timing Ts of the heat dissipation mode arrives after the reactor B is in the heat dissipation mode. In this way, by providing a temporal overlap t between the heat release modes that are sequentially executed by the three reactors A to C, one of the reactors A to C (for example, the reactor B) can release heat. Since the reactor A to C, which has been in the heat release mode until the time when sufficient exothermic reaction is obtained after the start of the mode, is compensated for the shortage of heat generation (eg, reactor A). The temporal variation of the heating efficiency of the combustion air by the chemical heat pump 5 can be further effectively suppressed. In this embodiment, the standby mode is set after the heat storage mode. However, when the standby mode is set after the heat release mode as shown in FIG. 4B described above, the heating efficiency time of the combustion air is provided by providing a similar temporal overlap. Fluctuations can be suppressed.

(Second Embodiment)
Next, an industrial furnace 2 including a burner device 1 according to a second embodiment of the present invention will be described with reference to FIGS. 8 to 10C. In these drawings, the same elements as those in the first embodiment are denoted by the same reference numerals.

  The burner device 1 in this embodiment is a regenerative burner, and includes two pairs of burners 3A and 3B. Thermal storage chambers 32A and 32B in which the thermal storage bodies 31A and 31B are accommodated are provided for the individual burners 3A and 3B. Referring to FIG. 8, the downstream air line 7b, which is a part of the air line 7 to the combustion air fan 8 and the burners 3A, 3B, is connected to the individual heat storage chambers 32A, 32A via the air supply switching valves 33A, 33B. 32B. Referring to FIG. 8, the upstream side exhaust gas line 9a of the exhaust gas line 9 is connected to the individual heat storage chambers 32A and 32B via the exhaust gas switching valves 34A and 34B on the upstream side. Further, the downstream exhaust gas line 9 b of the exhaust gas line 9 is connected to the exhaust gas suction fan 35 on the downstream side. As shown only in FIG. 8, the exhaust gas line 9 is provided with an adjustment valve 41 for adjusting the amount of exhaust gas passing through the chemical heat pump 5.

  The controller 27 controls the opening and closing of the air supply switching valves 33A and 33B and the exhaust switching 34A and 34B, and switches the two burners 3A and 3B between the combustion side and the exhaust side at regular intervals. For example, the air supply switching valve 33A is opened, the intake side switching valve 33B is closed, and the exhaust switching valve 34A is closed to open the exhaust side switching valve 34B (first state). In this first state, the combustion air supplied from the combustion air fan 8 is preheated by the chemical heat pump 5 and the heat storage body 31A, and is jetted together with the fuel by the burner 3A to burn the fuel in the furnace. In the first state, the combustion exhaust gas in the furnace is exhausted after passing through the heat storage body 31B in the heat storage chamber 32B by suction of the exhaust gas suction fan 35, and heat is exchanged at that time to heat the heat storage body 31B. That is, in the first state, the burner 3A is on the combustion side and the burner 3B is on the exhaust side, and the heat storage body 31B on the exhaust side is heated. When the open / close state of the supply air switching valves 33A, 33B and the exhaust gas switching valves 34A, 34B is opposite to the first state (second state), the burner 3B becomes the combustion side and the burner 3A becomes the exhaust side, and the exhaust side The heat storage body 31A is heated. Not all of the combustion exhaust gas generated in the furnace is exhausted through the exhaust gas line 9 by the suction of the exhaust gas suction fan 35, but a part is exhausted through the main exhaust gas line 36. For example, during combustion by one burner 3A, the air sent from the combustion air fan 8 is first heated by performing heat exchange (primary heat exchange) with a chemical heat storage material 14 (to be described later) in the chemical heat pump 5, and then burner 3A side. The heat storage body 31A of the heat storage chamber 32A (heated during combustion by the other burner 3B) is further heat-exchanged.

  The configuration of the chemical heat pump 5 is the same as that of the first embodiment. Further referring to FIG. 9, the inlets of the first heat exchanger 15 of the three reactors A to C (containing the chemical heat storage material 14 such as calcium sulfate) provided in the chemical heat pump 5 are the heat storage bodies 31A, 31A, The upstream bypass line 17a branched from the exhaust gas line 9 downstream of 31B is connected to the exhaust gas inlet valve 18a, while the outlet of the first heat exchanger 15 is connected to the downstream bypass line 18b via the exhaust gas outlet valve 18b. 17b (joins the exhaust gas line 9). The inlets of the first heat exchangers 15 of the reactors A to C are connected via an upstream air line 7a connected to the combustion air fan 8 and an air inlet valve 16a, while the first heat exchanger 15 The outlet is connected to the downstream air line 7b through an air outlet valve 16b. Furthermore, the reactors A to C are connected to the condenser 11 by a steam extraction line 21 provided with a steam outlet valve 22b, and are connected to the evaporator 13 by a steam supply line 23 provided with a steam inlet valve 22a. . The condenser 11 and the evaporator 13 are connected by a condensed water supply line 25 having a partition valve 24 interposed therebetween.

  As in the first embodiment, as shown in FIGS. 10A to 10C, the air inlet valve 16a, the air outlet valve 16b, the exhaust gas inlet valve 18a, the exhaust gas outlet valve 18b, the steam inlet valve 22a, and the steam outlet valve 22b are opened and closed. The three reactors A to C repeat the heat storage mode, the standby mode, and the heat release mode in this order, and the cycle of repeating the mode between the reactors A to C is shifted from each other.

  The burner device 1 of this embodiment has the following characteristics.

  Combustion air can be heated with high efficiency by combining the chemical heat pump 5 with the regenerative burner (heat storage elements 31A and 31B). For example, it is possible to store heat from combustion exhaust gas at about 200 ° C. after heat exchange with the heat storage bodies 31A and 31B and to heat the combustion air. In particular, when the burner device 1 is newly installed, the heat storage bodies 31A and 31B can be reduced in size by heating the combustion air with high efficiency using the chemical heat pump 5, and the exhaust gas suction rate can also be reduced. Here, the exhaust gas suction rate is the combustion exhaust gas used for heating the heat storage bodies 31A and 31B with respect to the entire combustion exhaust gas discharged through the exhaust gas line 9 and the main exhaust gas line 36 (the combustion exhaust gas discharged through the exhaust gas line 9). ). By reducing the exhaust gas suction rate, the capacity of the exhaust gas suction fan 35 can be reduced. Moreover, the amount of high-temperature exhaust gas discharged from the main exhaust gas line 36 without being used for heating the heat storage bodies 31A and 31B increases, and the amount of heat recovered by, for example, a waste heat recovery boiler can be increased.

  In both cases where the burner device 1 is newly installed and existing, the switching time of the burners 3A and 3B is extended by combining the chemical heat pump 5 with the regenerative burner to improve the heating efficiency of the combustion air. As a result, for example, equipment for switching the burners 3A and 3B, such as the air supply switching valves 33A and 33B and the exhaust switching valves 34A and 34B, can have a long life. By extending the burner switching time, fluctuations in temperature and pressure generated in the furnace when the burners 3A and 3B are switched can be suppressed, and the uniformity in the furnace is improved.

  In the case of the existing burner apparatus 1, the exhaust gas suction rate can be reduced by combining the regenerative burner with the chemical heat pump 5 to improve the heating efficiency of the combustion air. The amount can be increased.

  Since other configurations and operations of the second embodiment are the same as those of the first embodiment, the same elements are denoted by the same reference numerals and description thereof is omitted.

  The present invention is not limited to the embodiments, and various modifications are possible as listed below.

  As shown in FIG. 11, the chemical heat pump 5 may include two reactors A and B in the first embodiment. Similarly, as shown in FIG. 12, in the second embodiment, a configuration in which the chemical heat pump 5 includes two reactors A and B is also possible. In this case, the individual reactors A and B repeat the heat storage mode and the heat release mode. Further, while one of the two reactors A and B is in the heat storage mode, the other is in the heat dissipation mode.

  The chemical heat storage material of the chemical heat pump 5 is not limited to the calcium hydroxide exemplified in the embodiment. There is a temperature range that is more suitable for the characteristics of the chemical substance used as a chemical heat storage material, and it can handle a wide range of input temperatures by selecting the substance.

  The air line 7, the exhaust gas line 9, and the like are not necessarily configured as pipe lines, and a part or all of them may be configured by a gas flow path formed in, for example, a furnace wall.

DESCRIPTION OF SYMBOLS 1 Burner apparatus 2 Industrial furnace 3,3A, 3B Burner 4 Recuperator 5 Chemical heat pump 7 Air line 7a Upstream air line 7b Downstream air line 8 Combustion air fan 9 Exhaust gas line 11 Condenser 12 Cold heat source 13 Evaporator 14 Chemical heat storage material DESCRIPTION OF SYMBOLS 15 1st heat exchanger 16a Air inlet valve 16b Air outlet valve 17 Detour line 17a Upstream detour line 17b Downstream detour line 18a Exhaust gas inlet valve 18b Exhaust gas outlet valve 19 2nd heat exchanger 21 Steam extraction line 22a Steam inlet valve 22b Steam outlet valve 23 Steam supply line 24 Partition valve 25 Condensate supply line 27 Controller 31A, 31B Heat storage body 32A, 32B Heat storage chamber 33A, 33B Air supply switching valve 34A, 34B Exhaust switching valve 35 Exhaust gas suction fan 36 Main exhaust gas line 41 Adjusting valve

Claims (7)

With a burner,
A main heat exchange section for preheating combustion air supplied to the burner with heat recovered from the combustion exhaust gas of the burner;
A chemical heat pump that absorbs heat from the combustion exhaust gas before or after being supplied to the main heat exchange unit and releases the absorbed heat to the combustion air before being supplied to the burner.   The burner apparatus according to claim 1, wherein the main heat exchange unit is a recuperator.   The burner apparatus according to claim 1, wherein the main heat exchanging unit is a heat storage body of a regenerative burner. The chemical heat pump is
A chemical heat storage material is accommodated, and a reaction section provided with a heat exchanger for heat exchange between the chemical heat storage material and the combustion exhaust gas and the combustion air, and the chemical heat storage material is combusted in the reaction section. Condensation and evaporation of the product that is taken out from the exhaust gas from the reaction unit and condensed, and the product is evaporated when the chemical heat storage material dissipates heat to the combustion air in the reaction unit. The burner device according to claim 1, further comprising: The chemical heat pump includes three or more reaction parts,
Each of the reaction units includes a heat storage mode in which the chemical heat storage material absorbs heat from the combustion exhaust gas, a standby mode in which heat exchange is not performed between the chemical heat storage material, the combustion exhaust gas, and the combustion air, and the chemical heat storage. Repeat the heat dissipation mode in which the material dissipates heat to the combustion air,
The burner apparatus according to claim 4, wherein a cycle of repeating the heat storage mode, the standby mode, and the heat dissipation mode is shifted between the three or more reaction units.   The burner device according to claim 5, wherein the start timing of the heat release mode in the next reaction section comes before the end timing of the heat release mode of each of the reaction sections.   An industrial furnace provided with the burner apparatus of any one of Claims 1-6.

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