JP4603251B2 - Steam reforming furnace - Google Patents

Description

  The present invention relates to a steam reforming furnace using a regenerative combustion burner.

  Conventionally, the inside of a furnace body is heated to a predetermined temperature using a regenerative combustion burner equipped with a regenerative heat exchanger that heats combustion air using the heat of combustion gas discharged from the inside of the furnace body, and a regenerative type Preheat the process fluid supplied to the raw material and / or the reaction tube in the furnace body using the heat of the combustion gas discharged from the regenerative heat exchanger in a separate heat exchanger arranged in the front stage of the heat exchanger A steam reforming furnace has been proposed.

  When an intake / exhaust switching type heat accumulator is used for preheating combustion air in a steam reforming furnace, for example, a hydrogen plant, a methanol plant, a dimethyl ether (DME) plant, a gas-to-liquid (GTL) plant, or the like. When using a gas with a low calorific value (low heating value: unit kJ / kg), a water equivalent ratio between combustion exhaust gas (hereinafter referred to as combustion gas) and air (exhaust gas and air for heat exchange) Therefore, the temperature of the exhaust gas from the heat storage body is so high that it cannot be discharged into the atmosphere as it is.

In the case of natural gas (city gas) fuel, the water equivalent ratio is about 1.3. When the air is preheated from 15 ° C. to 1000 ° C., the temperature of the exhaust gas is 1100 ° C. → 350 ° C. The water equivalent ratio is (1000-15) / (1100-350) = 1.31. However, in a hydrogen plant, the entire amount of PSA gas purification off-gas (herein, PSA is an abbreviation of Pressure Swing Adsorption) is used in the reforming furnace as fuel, so the calorific value of the fuel is low and the water equivalent ratio is about 1.55 It becomes. The temperature of the exhaust gas is about 465 ° C. That is, (1000-15) / (1100-465) = 1.55. If the exhaust gas at 465 ° C. is released into the atmosphere as it is, energy is lost and heat recovery is performed. In particular, the temperature of the raw material + steam introduced to the reaction side of the reforming furnace was normally raised to about 500 ° C. by the convection section of the reforming furnace. In WO98 / 14536, a regenerative combustion burner provided with a regenerative heat exchanger that heats combustion air using the heat of combustion gas discharged from the furnace body using a convection section, An example of another conventional reforming furnace for heating a reaction tube in a furnace body to a predetermined temperature is shown. In this prior art, the temperature of the combustion air supplied into the furnace body from the regenerative heat exchanger provided for the furnace body is set to 1000 ° C. or more, and a part of the combustion gas in the furnace body is used as a convection part The exhaust heat of the combustion gas is effectively utilized by flowing and recovering the exhaust heat with a heat recovery device.
WO98 / 14536 (FIG. 1)

  However, the above-described prior art requires a heating coil made of a high-temperature material, and there is a problem that the construction cost increases. Therefore, in a reforming furnace using a heat storage body for air preheating, a convection part is not actually used. Therefore, since there is no high-temperature heating source, the temperature of the raw material + steam (process fluid) is lowered, and as a result, there is a problem that the required endothermic amount on the reaction side of the reforming furnace is increased.

  The objective of this invention is providing the steam reforming furnace which can raise the temperature of the process fluid supplied to a reaction tube, without using a convection part.

  In addition to the above object, another object of the present invention is to provide a steam reforming furnace that does not require the use of a highly heat-resistant switching valve device when using an alternating heat storage heat exchanger.

  Still another object of the present invention is to provide a steam reforming furnace capable of extending the life of the switching valve device of the regenerative heat exchanger.

  The steam reforming furnace to be improved by the present invention uses a regenerative combustion burner provided with a regenerative heat exchanger that heats combustion air using the heat of combustion gas discharged from the interior of the furnace body. The furnace body is heated to a predetermined temperature. Then, in a separate heat exchanger arranged in the front stage of the heat storage type heat exchanger, a process for supplying the raw material and / or the reaction tube in the furnace body using the heat of the combustion gas discharged from the heat storage type heat exchanger Preheat fluid.

  As the separately installed heat exchanger, any type of heat exchanger including a heat storage type can be used, and the type of heat exchanger is not limited to a specific type.

  As the heat storage type combustion burner, for example, a well-known continuous combustion type heat storage type combustion burner disclosed in JP-A-11-223335 and JP-A-2000-39138 can be used. This type of continuous combustion regenerative combustion burner has a regenerator divided into one burner, supplies combustion air to some regenerators, and at the same time the other regenerators emit combustion gases. Heat is stored by suction. The flow paths for air supply and combustion gas discharge are switched at a constant cycle, and heat storage / heat radiation is repeated inside one burner system. The discharge port of the high-temperature air moves in the circumferential direction along with switching, but the fuel can be continuously supplied from one burner. As the heat storage combustion burner, a so-called alternating heat storage combustion burner can also be used. An alternating-type regenerative combustion burner heats combustion air with sensible heat of the heat storage body by alternately flowing combustion air and combustion gas over the entire heat storage body. There are a continuous combustion type and an intermittent combustion type that intermittently burns the burner. The continuous combustion type is disclosed in, for example, Japanese Patent Laid-Open Nos. 5-256423 and 6-11121. An example of the intermittent combustion type is disclosed in JP-A-1-222102. In the reforming furnace, one or more regenerative combustion burners are used. When using a plurality of regenerative combustion burners, separate exchangers may be provided for each regenerative combustion burner. However, even if a plurality of regenerative heat exchangers and a plurality of separate heat exchangers are connected so that one or a plurality of separate exchangers are used for a plurality of regenerative combustion burners. Of course it is good.

  In the present invention, the separate heat exchanger is configured to preheat the combustion air. That is, the combustion air is positively preheated by a separate heat exchanger, and the preheated combustion air is further heated by a regenerative heat exchanger. As a result, for example, combustion air can be heated to 800 ° C. or higher, and high-temperature air combustion can be realized as a combustion mode. If the combustion air is preheated in the previous stage of the heat storage type heat exchanger, the temperature of the combustion gas discharged from the heat storage type heat exchanger will increase accordingly. As a result, since the temperature of the combustion gas supplied to the separately placed heat exchanger can be made higher than before, the preheating temperature of the raw material and / or process fluid in the separately placed heat exchanger can be obtained without using a convection section. Can be high.

  The present invention can also be applied to the case of using a regenerative combustion burner provided with an alternating regenerative heat exchanger. The alternating heat storage heat exchanger includes a plurality of pairs of heat storage elements, and alternately stores the combustion gas discharged from the furnace body through the pair of heat storage elements to store the heat of the combustion gas in the heat storage elements. The combustion air is heated by alternately flowing the combustion air through the pair of heat storage bodies and using the heat stored in the heat storage body. And in the separate heat exchanger arranged in the front stage of the alternating heat storage heat exchanger, the heat of the combustion gas discharged from the alternating heat storage heat exchanger is used to supply the raw material and / or the furnace body. Preheat the process fluid supplied to the reaction tube. In this case, when the separate heat exchanger is discharged with combustion gas from one of the two heat exchangers provided corresponding to the pair of heat storage bodies and one of the pair of heat storage bodies When the combustion gas is discharged through one heat exchange section of the two heat exchange sections and the combustion gas is discharged from the other heat storage body among the pair of heat storage bodies, the other heat exchange of the two heat exchange sections And a switching valve device that switches use of the two heat exchange units so that the combustion gas is discharged through the unit. And the switching valve apparatus is arrange | positioned at the low temperature side of two heat exchange parts. In this way, since the switching valve device is arranged on the low temperature side of the two heat exchange units and the two heat exchange units are switched and used, the heat resistant temperature of the switching valve device can be lowered. As a result, not only can the switching valve device be configured using an inexpensive switching valve with low heat resistance, but the life of the switching valve device can be extended, and the life of the separately installed heat exchanger can be extended.

  In addition, when using a regenerative combustion burner with an alternating regenerative heat exchanger, a separate heat exchanger is configured to preheat combustion air, and further supports a pair of regenerative bodies. Two additional heat exchangers and a switching valve device may be provided. The switching valve device discharges a part of the combustion gas through one additional heat exchanger of the two additional heat exchangers when the combustion gas is discharged from one of the pair of heat storage bodies. The combustion air preheated by the separate heat exchanger is further heated through the additional heat exchanger, and when the combustion gas is discharged from the other heat accumulator, the other additional heat exchanger passes through the other additional heat exchanger. Configured to switch the use of the two additional heat exchangers so as to further heat the combustion air pre-heated by the separate heat exchanger through a part of the combustion gas and through the other additional heat exchanger To do. In addition, the switching valve device is arranged on the low temperature side of the two additional heat exchangers. If such a configuration is adopted, the combustion gas discharged from the heat storage body can be divided into both the separately installed heat exchanger and the additional heat exchanger, so that the combustion gas is supplied to the separately installed heat exchanger side. The total amount of heat applied to the switching valve used in the road can be reduced. Furthermore, a separate heat exchanger having two heat exchange units corresponding to the two heat storage members may be provided, and the switching valve may be disposed on the low temperature side of the two heat exchange units. Moreover, since the heat resistance of the switching valve device arranged on the low temperature side of the two additional heat exchangers may be low, the life of the switching valve device can be extended. In this case, if a damper for adjusting the amount of combustion gas passing through the additional heat exchanger is arranged between the switching valve device and the induction blower, the partial flow rate is appropriately adjusted by adjusting the opening of the damper. Therefore, it is possible to easily adjust the preheating temperature of combustion air, raw material, and process fluid. If a plate heat exchanger is used as the additional heat exchanger, the purpose can be achieved without significantly increasing the price of the entire reforming furnace.

If the raw material preheated in the separate heat exchanger is further heated with the heat recovered in the heat exchanger provided downstream of the high-temperature shift converter installed downstream of the furnace body, the amount of heat exchange in the separate heat exchanger Even if there is little, a raw material can be preheated to required temperature.

  The separate heat exchanger can be configured to preheat the raw material in two stages by the first and second heating coils. In this case, a heating coil of a waste heat boiler that is used as an auxiliary heat source of a steam generator that generates steam may be disposed between the first and second heating coils. When such a configuration is adopted, the temperature of the steam can be raised by a separate heat exchanger, and as a result, the temperature of the process fluid can be raised without using a convection section.

  According to the present invention, since the temperature of the combustion gas supplied to the separate heat exchanger can be made higher than before, the raw material and / or process fluid in the separate heat exchanger can be used without using a convection section. There is an advantage that the preheating temperature can be increased.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of an example of an embodiment in which the present invention is applied to a steam reforming furnace of a hydrogen plant using a high-temperature air combustion technique. What is indicated by reference numeral 1 is a furnace body having a combustion chamber 2 inside. One or more regenerative combustion burners are fixed to the furnace wall 1 a of the furnace body 1. In FIG. 1, one regenerative heat exchanger 3 and a burner 4 provided with this regenerative combustion burner are shown. A plurality of reaction tubes 5 are arranged so as to penetrate the bottom wall 1b and the top wall 1c of the furnace body 1.

  The regenerative heat exchanger 3 of the regenerative combustion burner used here is an alternating regenerative heat exchanger as shown in FIG. The heat storage type heat exchanger 3 is configured such that two heat storage bodies 6 and 7 that form a pair having air permeability and combustion gas in the combustion chamber 2 flow alternately to the heat storage body 6 or 7, and the two heat storage bodies 6 and 7 And a switching valve device 8 that heats the combustion air with sensible heat and supplies the combustion air into the combustion chamber 2. In the actual apparatus, a plurality of pairs of heat storage bodies are provided, but in the following description, it is assumed that only two heat storage bodies 6 and 7 are provided for convenience of explanation.

  The switching valve device 8 includes two switching valves 9 and 10 provided for the heat storage body 6 and two switching valves 11 and 12 provided for the heat storage body 7. These switching valves 9 to 12 are driven and controlled by driving means (not shown). In FIG. 2, a black circle mark indicates that the switching valve is in an open state, and a mark with a horizontal line drawn on the black circle indicates that the switching valve is in a closed state. Moreover, in FIG. 2, the arrow has shown the direction through which a fluid flows.

  A separate heat exchanger 13 is disposed in the front stage of the alternating heat storage type heat exchanger 3 (on the side opposite to the furnace body 1). The separate heat exchanger 13 uses the heat of the combustion gas discharged from the alternating heat storage heat exchanger 3 and the raw material and the process fluid supplied to the reaction tube 5 in the furnace body 1 (raw material + Steam) and the combustion air supplied to the heat storage bodies 6 and 7 are preheated. The structure of the separate heat exchanger 13 is arbitrary, and the combustion gas is sucked into the interior from the combustion chamber 2 through the heat accumulator 6 or 7 by the induced air blowing force of the induction fan 14. In the separate heat exchanger 13, a first heating coil 15 for heating the process fluid (raw material + steam), a second heating coil 16 (not shown in FIG. 2) for heating the raw material, and combustion And a third heating coil 17 for heating the working air. The first to third heating coils 15 to 17 are arranged in order from the upstream side to the downstream side from the first heating coil 15 toward the third heating coil 17. In FIG. 1, the temperature displayed on the side of each heating coil indicates the temperature of the combustion gas passing through the place where each heating coil is disposed. In this example, the temperature of the combustion gas emitted from the alternating-type regenerative heat exchanger 3 is 655 ° C., the temperature of the combustion gas passing through the place where the first heating coil 15 is disposed is 408 ° C., and the second heating It is shown that the temperature of the combustion gas that has passed through the location of the coil 16 is 348 ° C., and the temperature of the combustion gas that has passed through the location of the third heating coil 17 is 155 ° C.

  The combustion air is heated to about 300 ° C. by the third heating coil 17, is subjected to heat exchange heating, and is supplied to the heat storage body 6 or 7 of the heat storage heat exchanger 3. The combustion air is further heated to about 1000 ° C. by the heat accumulator 6 or 7 and supplied into the combustion chamber 2. Since the temperature of the combustion air supplied to the heat accumulator 6 or 7 is high, the temperature drop when the combustion gas passes through each heat accumulator 6 or 7 is small. It does not decline. Therefore, a necessary amount of heat can be supplied in the separate heat exchanger 13.

  Combustion air is pushed into the heat accumulator 6 or 7 from the pusher blower 18 via the heating coil 17. The raw material heated by the heating coil 16 is supplied to the hydrogenation reactor 19 and the desulfurization reactor 20. Steam is added to the outlet of the desulfurization reactor 20 to create a process fluid. The process fluid is supplied to the first heating coil 15, heated, and supplied to the reaction tube 5. In this example, the process fluid at 244 ° C. is heated by the first heating coil 15 to 485 ° C.

  The process fluid heated and reformed in the reaction tube 5 to 850 ° C. has its temperature lowered to 350 ° C. through the heat exchanger 21 and is heated again in the high temperature shift converter 22 to 415 ° C. The temperature is lowered in the vessel 23 and is supplied to a pressure swing adsorption (PSA) gas purifier. The heat exchangers 21 and 23 are provided to obtain a heat source of the steam generator 24, and a heat transfer medium circulates between the heat exchangers 21 and 23 and the steam generator 24. ing. The steam generator 24 heats the water BFW for steaming using the amount of heat obtained from the heat exchangers 21 and 23 as a heat source, and outputs it as steam at 221 ° C. Excess steam is used in other heat exchangers.

  In the example of FIG. 1, the PSA gas refined off gas is supplied to the burner 4 together with normal fuel.

  As shown in FIG. 2, in this example, the switching valves 10 and 11 are closed when the switching valves 9 and 12 are open, and the switching valves 10 and 11 are closed when the switching valves 9 and 12 are closed. By being in the open state, the combustion gas flows alternately to the heat storage bodies 6 and 7, and the combustion air heated alternately is supplied to the heat storage bodies 7 and 6. According to the present embodiment, by preheating the air to be introduced into the heat storage bodies 6 and 7 using the separate heat exchanger 13, the temperature of the exhaust gas that exits from the heat storage bodies 6 and 7 can be positively increased. The raw material + steam can be preheated to the same extent as when the convection part is provided. Further, the recovery unit of the separate heat exchanger 13 thereafter can efficiently heat each fluid and perform heat recovery with a good balance. The combustion air is preheated to an appropriate balance temperature (300 ° C. in this case) at the last part of the heat recovery unit of the separately installed heat exchanger 13 and then introduced into the heat storage body 6 or 7. The combustion air is heated so that the temperature of the heat storage body is 300 ° C. → 1000 ° C. In this case, the combustion gas (exhaust gas) falls from 1100 ° C. to 649 ° C. Therefore, the water equivalent ratio is (1000−300) / (1100−649) = 1.55, but it is about 655 ° C. when the mass balance / heat balance is taken.

  However, in this embodiment, switching valves 9 and 11 that can withstand a high temperature of about 655 ° C. are required for switching between the heat storage bodies 6 and 7. Although there are valves that can withstand up to about 650 ° C., there is a problem that the price is high and the reliability is low. Therefore, if possible, it is desirable to use a switching valve used for the switching valve device at a low temperature. FIG. 3 shows a configuration of a main part of another embodiment capable of meeting such a demand. In this embodiment, the separate heat exchanger 13 includes two heat exchange units 13A and 13B provided corresponding to the two heat storage bodies 6 and 7, and the switching valves 10 and 12 and the heat exchange unit described above. And a switching valve device 25. When the combustion gas is discharged from one of the two heat storage bodies 6 and 7 (for example, the heat storage body 6), the switching valve device 25 of the heat exchange section is one of the two heat exchange sections 13A and 13B. When the combustion gas is discharged through the heat exchange part (for example, the heat exchange part 13A) and the combustion gas is discharged from the other heat storage body (for example, the heat storage body 7) of the two heat storage bodies 6 and 7, two heat exchanges are performed. The use of the two heat exchanging parts 13A and 13B is switched so that the combustion gas is discharged through the other heat exchanging part (for example, the heat exchanging part 13B) of the parts 13A and 13B. Specifically, the switching valve device 25 is constituted by the switching valves 26 and 27. In this embodiment, this switching valve device 25 is arranged on the low temperature side of the two heat exchange parts 13A and 13B. If the two heat exchange parts 13A and 13B are switched and used using the switching valve device arranged on the low temperature side in this way, the heat resistant temperature of the switching valve device 25 can be lowered. As a result, inexpensive switching valves with low heat resistance can be used as the switching valves 26 and 27, the life of the switching valve device can be extended, and the life of the separately installed heat exchanger can be extended. Further, since the switching valve 10 and the switching valve 26, and the switching valve 12 and the switching valve 27 always open and close in reverse, the number of switching valves is changed from four to two (switching valves) by using two-way valves respectively. 10 and 26 can be reduced to one two-way valve, and the switching valves 12 and 27 can be reduced to one two-way valve.

  FIG. 4 is a diagram showing a configuration of a main part of another embodiment that uses the highly heat-resistant switching valves 9 and 12 and can extend the life thereof. In this embodiment, when a regenerative combustion burner equipped with an alternating regenerative heat exchanger is used, the separate heat exchanger 13 is replaced with combustion air as in the embodiment of FIGS. In addition to being configured to preheat, two additional heat exchangers 28 and 29 and a switching valve device 34 including four switching valves (30 to 33) are provided corresponding to the two heat storage elements. In this example, recuperators (inexpensive plate type heat exchangers) used for mass production type micro gas turbines are used as the additional heat exchangers 28 and 29. When the combustion gas is discharged from one of the two heat storage bodies 6 and 7 (for example, the heat storage body 6), the switching valve device 34 is one of the two additional heat exchangers 28 and 29. A part of the combustion gas is discharged through (for example, the additional heat exchanger 28), and the combustion air preheated by the separate heat exchanger 13 is further heated through the additional heat exchanger (for example, the additional heat exchanger 28). Thus, the switching operation of the switching valves 30 to 33 is performed. Further, the switching valve device 34 discharges a part of the combustion gas through the other additional heat exchanger 29 of the two additional heat exchangers and discharges the other additional heat when the combustion gas is discharged from the other heat storage body 7. The switching operation of the switching valves 30 to 33 is performed to switch the use of the two additional heat exchangers so that the combustion air preheated by the separately installed heat exchanger 13 is further heated through the exchanger 29. In this example, the switching valve device 34 is disposed on the low temperature side of the two additional heat exchangers 28 and 29. In this embodiment, a damper 35 for adjusting the amount of combustion gas passing through the additional heat exchangers 28 and 29 is disposed between the switching valve device 34 and the induction blower 14. By adjusting the opening degree of the damper 35, the partial flow rate can be adjusted appropriately, so that the preheating temperatures of the combustion air, the raw material, and the process fluid can be easily adjusted.

  In this embodiment, the switching valves 9 and 12 for exhaust gas for heating the process fluid remain. Further, in order to reduce the amount of combustion gas (exhaust gas) passing through the switching valves 9 and 12, additional heat exchangers 28 and 29 are installed for the heat storage bodies 6 and 7 by dividing the flow path. It is assumed that the combustion gas (exhaust gas) emitted from the additional heat exchangers 28 and 29 is recovered to about 150 ° C., and the combustion air introduced into the additional heat exchangers 28 and 29 is about 100 ° C. An approach temperature of 50 ° C. between 100 ° C. and 150 ° C. in a recuperator is a temperature difference that has already been proven and is sufficiently reachable. The combustion air is preheated to a predetermined temperature (300 ° C. in this case), and the combustion gas (exhaust gas amount) necessary for this is diverted from the heat accumulators 6 and 7.

  According to this embodiment, the combustion gas discharged from the heat accumulators 6 and 7 can be divided into both the separately placed heat exchanger 13 and the additional heat exchanger 28 or 29. Therefore, the separately placed heat exchanger 13 The total amount of heat applied to the switching valve used in the flow path for supplying the combustion gas to the side can be reduced. Moreover, since the heat resistance of the switching valve device 34 disposed on the low temperature side of the two additional heat exchangers 28 and 29 may be low, the life of the switching valve device 34 can be extended.

FIG. 5 is a diagram showing a configuration of still another embodiment of the present invention. This embodiment is different from the embodiment of FIG. 1 in that only a part of the combustion gas discharged from the heat storage bodies 6 and 7 is caused to flow separately to the heat exchanger 13 using the switching valve device 37. In addition, the raw material heated by the second heating coil 16 is not immediately supplied to the hydrogenation reactor 19, but is heated again by the heat exchanger 36 newly added after the high temperature shift converter 22, The other points are the same as those in the embodiment shown in FIGS. 1 and 2. In such an embodiment, the amount of heat necessary for the separate heat exchanger 13 is insufficient because the amount of exhaust gas (combustion gas) introduced into the separate heat exchanger 13 is reduced. Therefore, in this example, in the case of a hydrogen plant, a heat exchanger 36 is provided downstream of the high temperature shift converter 22 that is currently generating steam to recover heat and cover the shortage. If the raw material preheated in the separate heat exchanger 13 is further heated with the heat recovered from the heat exchanger 36 provided downstream of the high temperature shift converter 22 on the downstream side of the furnace body as in this embodiment, the separate material is placed. Even when the amount of heat exchange in the heat exchanger is small, the raw material can be preheated to a required temperature.

  In the example of FIG. 6, the raw material is preheated in two stages by two heating coils 16 </ b> A and 16 </ b> B (first and second heating coils) in the separate heat exchanger 13. Further, a heating coil 37 of a waste heat boiler used as an auxiliary heat source of the steam generator 24 that generates steam is disposed in the heat exchanger 13 separately between the two heating coils 16A and 16B. Further, the output of the steam generator 24 is further heated by a heat exchanger 36 provided downstream of the high temperature shift converter 22. By adopting such a configuration, the temperature of the steam can be raised by the heat exchanger 36, and as a result, the temperature of the process fluid can be raised without using the convection section. In this embodiment, by raising the temperature of the steam added to the raw material gas, the amount of heat necessary for heating the raw material + steam is lowered, and the raw material gas can be raised to the predetermined temperature by the exhaust gas. In FIGS. 5 and 6, as in FIG. 1, the temperature of each part is displayed on the diagram for reference.

  In any of the above embodiments, the present invention is applied to a reforming furnace using a high-temperature air combustion technique, but it is needless to say that the present invention can also be applied to a general reforming furnace of the present invention.

  In the above embodiment, the present invention is applied to a steam reforming furnace used in a hydrogen plant. However, the present invention is not limited to a methanol plant, a dimethyl ether (DME) plant, a gas-to-liquid (GTL) plant, or the like. Naturally, it can also be applied to a steam reforming furnace.

1 is a schematic configuration diagram of an example of an embodiment in which the present invention is applied to a steam reforming furnace of a hydrogen plant using a high-temperature air combustion technique. It is a figure used in order to demonstrate the structure and operation | movement of the principal part of embodiment of FIG. It is a figure used in order to demonstrate the structure and operation | movement of the principal part of other embodiment of this invention. It is a figure used in order to demonstrate the structure and operation | movement of the principal part of further another embodiment of this invention. It is a figure which shows the structure of other embodiment of this invention. It is a figure which shows the structure of other embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 Furnace body 2 Combustion chamber 3 Heat storage type heat exchanger 4 Burner 5 Reaction tube 6,7 Heat storage body 8 Switching valve apparatus 9-12 Switching valve 13 Separately installed heat exchanger 15-17 Heating coil

Claims (8)

Heat the furnace body to a predetermined temperature using a heat storage combustion burner equipped with a heat storage heat exchanger that heats the combustion air using the heat of the combustion gas discharged from the furnace body,
Supplying to the raw material and / or the reaction tube in the furnace body using the heat of the combustion gas discharged from the heat storage type heat exchanger in a separate heat exchanger arranged at the front stage of the heat storage type heat exchanger A steam reforming furnace for preheating a process fluid to be produced,
The steam reforming furnace, wherein the separate heat exchanger is configured to preheat the combustion air. A plurality of pairs of heat storage bodies are provided, and combustion gas discharged from the furnace body is alternately flowed through the pair of heat storage bodies to store heat of the combustion gas in the heat storage bodies, and the pair of heat storage bodies The inside of the furnace body is predetermined using a regenerative combustion burner provided with an alternating regenerative heat exchanger that heats the combustion air using the heat stored in the regenerator by alternately flowing combustion air. Heating to temperature,
Raw material and / or the furnace main body using heat of the combustion gas discharged from the alternating heat storage heat exchanger in a separate heat exchanger arranged in the front stage of the alternating heat storage heat exchanger A steam reforming furnace for preheating a process fluid supplied to an inner reaction tube,
In the separate heat exchanger, the combustion gas is discharged from one of the two heat exchangers provided corresponding to the pair of heat accumulators and the pair of heat accumulators. Sometimes the combustion gas is discharged through one of the two heat exchanging portions, and when the combustion gas is discharged from the other heat storage body of the paired heat storage bodies, the two A switching valve device that switches use of the two heat exchange units so as to discharge the combustion gas through the other heat exchange unit of the heat exchange unit, and the switching valve device is on a low temperature side of the two heat exchange units A steam reforming furnace characterized by being arranged in A plurality of pairs of heat storage bodies are provided, and combustion gas discharged from the furnace body is alternately flowed through the pair of heat storage bodies to store heat of the combustion gas in the heat storage bodies, and the pair of heat storage bodies The inside of the furnace body is predetermined using a regenerative combustion burner provided with an alternating regenerative heat exchanger that heats the combustion air using the heat stored in the regenerator by alternately flowing combustion air. Heating to temperature,
Raw material and / or the furnace main body using heat of the combustion gas discharged from the alternating heat storage heat exchanger in a separate heat exchanger arranged in the front stage of the alternating heat storage heat exchanger A steam reforming furnace for preheating a process fluid supplied to an inner reaction tube,
The separate heat exchanger is configured to preheat the combustion air;
Furthermore, two additional heat exchangers provided corresponding to the pair of heat storage bodies and the two additional heats when the combustion gas is discharged from one of the pair of heat storage bodies Exhausting part of the combustion gas through one of the additional heat exchangers of the exchanger and further heating the combustion air preheated by the separate heat exchanger through the one of the additional heat exchangers; When the combustion gas is discharged from the other heat storage body, a part of the combustion gas is discharged through the other additional heat exchanger of the two additional heat exchangers and the other additional heat exchanger is used to A switching valve device for switching the use of the two additional heat exchangers so as to further heat the combustion air preheated by the standing heat exchanger, and the switching valve device includes the two additional heat exchangers. Low temperature side Steam reforming furnace, characterized in that it is arranged.   The steam reforming furnace according to claim 3, wherein a damper that adjusts an amount of the combustion gas that passes through the additional heat exchanger is disposed between the switching valve device and the induction blower.   The steam reforming furnace according to claim 3, wherein the additional heat exchanger is a plate-type heat exchanger. The said raw material pre-heated with the said separate heat exchanger is further heated with the heat | fever collect | recovered with the heat exchanger provided in the downstream of the high temperature shift converter installed in the downstream of the said furnace main body. The steam reforming furnace according to 2 or 3.   The steam reformer according to claim 1, 2, 3, or 6, wherein the separate heat exchanger is configured to preheat the raw material in two stages by first and second heating coils. Quality furnace.   The steam reforming furnace according to claim 7, wherein a heating coil of a waste heat boiler used as an auxiliary heat source of a steam generator for generating steam is disposed between the first and second heating coils.

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