Heat storage combustion system and operation method thereof

Abstract

The invention relates to the field of combustion smelting systems, in particular to a heat storage combustion system and an operation method thereof.The system comprises a smelting furnace, and a hearth is arranged in the smelting furnace; a burner is arranged on the smelting furnace; the heat exchanger comprises a first channel and a second channel. A heat storage medium capable of storing heat is arranged in the first channel; a gas inlet of the hearth is communicated with a gas outlet end of the second channel; the air blowing mechanism comprises an air blower and a valve; the valve piece comprises a first state and a second state, in the first state, the air outlet end of the air blower communicates with the air inlet of the hearth through the valve piece, and the valve piece is cut off between the air outlet end of the air blower and the air inlet end of the second channel; in the second state, the valve piece is cut off between the air outlet end of the air blower and the air inlet of the hearth, and the air outlet end of the air blower is communicated with the air inlet end of the second channel through the valve piece; according to the scheme, waste heat of high-temperature waste gas generated by combustion can be recycled, so that the purpose of saving energy is achieved, and valves do not need to be frequently switched.

Description

Technical Field

[0001] The present application relates to the field of combustion melting systems, and in particular, to a regenerative combustion system and an operation method thereof. Background Art

[0002] Casting is the first process in metal processing in the casting industry. The main production process is: raw materials (aluminum ingots, iron ingots, etc.) → melting furnace → holding furnace → on-line degassing device → filter box → liquid level control diverter → casting machine → finished product. The main equipment includes melting furnaces, holding furnaces, and casting machines, etc. Among them, the melting furnace is an essential equipment in the casting plant, and its main function is to provide qualified molten metal to the casting machine.

[0003] In the combustion system composed of melting furnaces, with the progress of technology, the industrial combination of the commutation combustion technology and the regenerative technology has developed and popularized the "dispersion combustion technology" (also known as the regenerative high-temperature air combustion technology). Compared with the traditional combustion technology, the dispersion combustion technology not only saves more fuel, but also has lower NO X emission.

[0004] To achieve dispersion combustion, in some related technologies, two regenerators are adopted, and a switching valve is used to switch the flue gas and air back and forth. For details, reference can be made to the technologies disclosed in patent documents with application numbers 201821772403.8, 201310101708.1, 201020661098.2, etc.

[0005] The disadvantage of this method is that there are problems of unsteady and intermittent combustion operations, which are likely to cause furnace temperature fluctuations and flameouts; the switching valve switches frequently, increasing the failure rate and the risk of gas leakage, and raising the operation and maintenance costs.

[0006] Another example is a dispersion type recycled aluminum melting furnace disclosed in application number 202010963357.5. This melting furnace heats the combustion-supporting air through a pipeline system to reach the temperature of the combustion-supporting air required for dispersion combustion, and can achieve a continuous and stable dispersion combustion state. The heat for heating the combustion-supporting air is through a direct heat absorption and heat release reaction of a regenerative heat exchanger arranged on the side of the melting mechanism, rather than recovering the waste heat of the discharged flue gas, so energy conservation is not achieved. Summary of the Invention

[0007] In order to solve at least one technical problem mentioned in the background art, the purpose of the present application is to provide a regenerative combustion system and an operation method thereof.

[0008] To achieve the above purpose, the present application provides the following technical solutions.

[0009] On the one hand, the present application provides a regenerative combustion system, including: Smelting furnace, with a hearth provided inside the smelting furnace; the hearth includes an air inlet and an exhaust outlet, and a burner is provided on the smelting furnace; Heat exchanger, which includes a first channel and a second channel that are connected for gas flow and can exchange heat with each other; a heat storage medium capable of storing heat is provided in the first channel; the exhaust outlet of the hearth is connected to the inlet end of the first channel; the air inlet of the hearth is connected to the outlet end of the second channel; Blowing mechanism, including a blower and a valve member, the air inlet of the hearth and the inlet end of the second channel are connected to the outlet end of the blower through the valve member, and the valve member can switch between a first state and a second state to switch the air flow direction of the blower; In the first state, the outlet end of the blower is connected to the air inlet of the hearth through the valve member, and the valve member cuts off between the outlet end of the blower and the inlet end of the second channel; In the second state, the valve member cuts off between the outlet end of the blower and the air inlet of the hearth, and the outlet end of the blower is connected to the inlet end of the second channel through the valve member.

[0010] As an optional implementation manner of the present application, the system further includes a pipeline assembly; the pipeline assembly includes a first pipeline and a second pipeline; The first end of the first pipeline is connected to the outlet end of the second channel, and the second end of the first pipeline is connected to the air inlet of the hearth; the first pipeline is also connected to the outlet end of the blower through a valve member; The first end of the second pipeline is connected to the inlet end of the second channel; the second end of the second pipeline is connected to the outlet end of the blower through a valve member.

[0011] As an optional implementation manner of the present application, the valve member includes a three-way valve, the three-way valve includes an air inlet valve port, two air outlet valve ports and a valve plate; the air inlet valve port is connected to the outlet end of the blower; among the two air outlet valve ports, one is connected to the first pipeline, and the other is connected to the second end of the second pipeline; the valve plate can act between the two air outlet valve ports to control the opening / closing of the corresponding air outlet valve port.

[0012] As an optional implementation manner of the present application, the valve member includes two valves, the second ends of the first pipeline and the second pipeline are connected through a connecting pipe, and the two valves are arranged on the connecting pipe at intervals; the position of the connecting pipe between the two valves is connected to the outlet end of the blower.

[0013] As an alternative embodiment of the present application, the heat exchanger is a shell-and-tube heat exchanger, which includes a shell and heat exchange tubes; the internal space of the shell includes a heat exchange chamber and an air inlet chamber and an air outlet chamber located at both ends of the heat exchange chamber respectively, and the air inlet chamber is communicated with the exhaust port of the furnace; the heat exchange tubes are arranged in the heat exchange chamber and are respectively communicated with the air inlet chamber and the air outlet chamber at both ends; the heat storage medium is arranged in the heat exchange tubes.

[0014] As an alternative embodiment of the present application, the heat storage medium is at least one of alumina balls, silicon carbide balls, and zirconia balls.

[0015] As an alternative embodiment of the present application, the system further includes a chimney, and the chimney is communicated with the air outlet end of the first channel.

[0016] As an alternative embodiment of the present application, a natural gas flowmeter is provided at the gas end for adjusting the consumption of natural gas; and / or an air flowmeter is provided at the air outlet end of the blower for adjusting the air volume output by the blower.

[0017] As an alternative embodiment of the present application, a temperature detection component for detecting temperature is provided in at least one of the following four parts: inside the furnace, between the exhaust port of the furnace and the air inlet end of the first channel, between the air outlet end of the second channel and the air inlet port of the furnace, and the air outlet end of the first channel.

[0018] On the other hand, the present application also provides an operation method for a regenerative combustion system. The operation method is applied to the above-mentioned regenerative combustion system, and the operation method includes the following steps: S1. System preheating, including the following steps: S11. Place the crucible inside the furnace before starting the system; S12. Switch the valve to the first state; S13. Start the blower and turn on the burner to carry out combustion. The hot air in the furnace flows through the exhaust port and through the first channel to heat the heat storage medium in the first channel; S2. When the temperature of the heat storage medium reaches the set value, switch the valve to the second state; S3. Put the material to be melted into the crucible in the furnace; S4. When the temperature of the material in the crucible reaches the set value, take out the crucible and pour out the melted material.

[0019] Compared with the prior art, the present application has the following beneficial effects: First, during the actual operation of the present application, through preheating the furnace chamber, on the one hand, the inside of the furnace chamber can be dried and the crucible inside the furnace chamber can be initially heated. On the other hand, the heat of the high-temperature waste gas generated during the preheating process can be recovered by the heat storage medium to raise the temperature of the heat storage medium to the set temperature value. The heat recovered by the heat storage medium can then be utilized in the subsequent smelting process to heat the air output by the blower to make it high-temperature air, which helps the combustion of natural gas to achieve diffusion combustion.

[0020] Secondly, the present application only needs to perform one valve component switching operation to achieve diffusion combustion. Compared with the existing method that requires multiple valve switchings, the operation is more convenient and can effectively reduce the problems of furnace temperature fluctuations and flameout caused by frequent valve switchings.

[0021] Moreover, in the present application, the waste heat of the exhaust gas during the combustion process is effectively recovered and utilized, achieving the purpose of energy conservation.

[0022] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become easily understood through the following description. Brief Description of the Drawings

[0023] By referring to the accompanying drawings and reading the detailed description below, the above and other purposes, features, and advantages of the exemplary embodiments of the present application will become easily understood. In the drawings, several embodiments of the present application are shown in an exemplary rather than restrictive manner, where: In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0024] Figure 1 Shows the structural schematic diagram of Embodiment 1 of the present application (the valve component is in the first state); Figure 2 Shows the structural schematic diagram of Embodiment 1 of the present application (the valve component is in the second state); Figure 3 Shows the structural schematic diagram of Embodiment 2 of the present application.

[0025] Description of the Reference Numerals in the Drawings: 1. Melting furnace; 11. Furnace chamber; 12. Air inlet; 13. Exhaust port; 14. Burner; 15. Crucible; 2. Heat exchanger; 21. Housing; 211. Heat exchange chamber, 212. Air inlet chamber; 213. Air outlet chamber; 22. Heat exchange tube; 23. Second channel; 231. Air outlet hole; 232. Air inlet hole; 3. Blower mechanism; 31. Blower; 32. Three-way valve; 32a. Air inlet valve port; 32b. Upper air outlet valve port; 32c. Lower air outlet valve port; 33. Valve plate; 4. Pipeline assembly; 41. First pipeline; 42. Second pipeline; 43. Third pipeline; 5. Chimney; 6. Connecting pipe; 51. Upper valve; 52. Lower valve. Detailed implementation manners

[0026] To make the objectives, features, and advantages of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0027] Embodiment 1 As Figure 1 and Figure 2 shown, this embodiment provides a regenerative combustion system, which is mainly used for the smelting or casting of materials (such as aluminum ingots and iron ingots); this system mainly adopts the diffusion combustion technology (also known as the regenerative high-temperature air combustion technology).

[0028] This system mainly includes a smelting furnace 1, a heat exchanger 2, a blower mechanism 3, a pipeline assembly 4, a chimney 5, etc. The following is a specific description of each component.

[0029] As Figure 1 shown, a furnace chamber 11 is provided in the smelting furnace 1. The material to be smelted is generally loaded in a crucible 15, and then the crucible 15 is placed in the furnace chamber 11 for high-temperature smelting.

[0030] Among them, the furnace chamber 11 includes an air inlet 12 and an exhaust port 13. In some embodiments, both the air inlet 12 and the exhaust port 13 are opened on the side wall of the smelting furnace 1 and are both connected to the furnace chamber 11; in addition, a natural gas burner 14 is provided on the upper side wall of the smelting furnace 1, and natural gas is burned through the burner 14; during operation, air enters the furnace chamber 11 from the air inlet 12, and the high-temperature waste gas generated by high-temperature combustion in the furnace chamber 11 is discharged from the exhaust port 13.

[0031] The heat exchanger 2 includes a first channel and a second channel 23 that are in gas flow communication and can exchange heat with each other; both the first channel and the second channel 23 have an air inlet end and an air outlet end, and the gas flow enters from the air inlet end and exits from the air outlet end.

[0032] A heat storage medium capable of storing heat is provided in the first channel. The heat storage medium can be one or several of alumina balls, silicon carbide balls, and zirconia balls, and the sizes of the alumina balls, silicon carbide balls, and zirconia balls are 5 mm to 20 mm.

[0033] In some embodiments, the heat exchanger 2 is preferably a shell-and-tube heat exchanger, and its specific structure is as follows: As Figure 1 shown, the heat exchanger 2 includes a shell 21 and heat exchange tubes 22; an enclosed internal space is formed inside the shell 21, and this internal space is vertically divided into a heat exchange chamber 211 and an air inlet chamber 212 and an air outlet chamber 213 respectively located at both ends of the heat exchange chamber 211. Specifically in this embodiment, as Figure 1 shown in the perspective view, the air inlet chamber 212 is located above the heat exchange chamber 211, and the air outlet chamber 213 is located below the heat exchange chamber 211; and both the air inlet chamber 212 and the air outlet chamber 213 are isolated from the heat exchange chamber 211.

[0034] The heat exchange tubes 22 include a plurality of tubes, and each heat exchange tube 22 is arranged vertically in the heat exchange chamber 211, and one end of the heat exchange tube 22 is communicated with the air inlet chamber 212, and the other end is communicated with the air outlet chamber 213; at this time, each heat exchange tube 22 forms a first channel, the air inlet chamber 212 forms the air inlet end of the first channel, and the air outlet chamber 213 forms the air outlet end of the first channel. The heat storage medium is filled in the heat exchange tubes 22.

[0035] In the heat exchange chamber 211, the gaps between the heat exchange tubes 22 and the gaps between the heat exchange tubes 22 and the inner wall of the shell 21 form a second channel 23. Thus, an air outlet hole 231 is opened in the upper part of the side wall of the shell 21 as the air outlet end of the second channel 23, and an air inlet hole 232 is opened in the lower part of the side wall of the shell 21 as the air inlet end of the second channel 23.

[0036] In this way, the air flow flowing in the first channel (i.e., the heat exchange tubes 22) and the air flow flowing in the second channel 23 will exchange heat through the heat exchange tubes 22.

[0037] In this embodiment, as Figure 1 shown, the pipeline assembly 4 is mainly used to realize the connection between each port. Specifically, the pipeline assembly 4 includes a first pipeline 41, a second pipeline 42, a third pipeline 43, etc. The following will be specifically described in combination with each specific structure.

[0038] The exhaust port 13 of the furnace 11 is communicated with the air inlet end of the first channel through the third pipeline 43, that is, one end of the third pipeline 43 is communicated with the exhaust port 13, and the other end is communicated with the air inlet chamber 212; the air outlet chamber 213 is communicated with the chimney 5; thus, as Figure 1 shown by the red arrow in, it is the flow path of the air flow in the preheating stage. The high-temperature waste gas generated by combustion in the furnace 11 flows through the exhaust port 13, the third pipeline 43, the air inlet chamber 212, the heat exchange tubes 22, and the air outlet chamber 213 in sequence, and finally is discharged from the chimney 5.

[0039] The air inlet 12 of the furnace chamber 11 is communicated with the air outlet end of the second passage 23 through the first pipeline 41, that is, the first end of the first pipeline 41 is communicated with the air outlet hole 231 on the side wall of the housing 21, and the second end of the first pipeline 41 is communicated with the air inlet 12 of the furnace chamber 11.

[0040] The air blowing mechanism 3 is mainly used to blow air into the furnace chamber 11 to assist combustion; the air blowing mechanism 3 includes a blower 31 and a valve member.

[0041] The air inlet 12 of the furnace chamber 11 and the air inlet end (i.e., the air inlet hole 232) of the second passage 23 are connected to the air outlet end of the blower 31 through a valve member, and the valve member can be switched between a first state and a second state to switch the air outlet flow direction of the blower 31; In the first state, that is Figure 1 In the state shown, in the first state, the air outlet end of the blower 31 is communicated with the air inlet 12 of the furnace chamber 11 through the valve member to allow the air flow output by the blower 31 to flow through the valve member to the air inlet 12; and, in the first state, the valve member also cuts off between the air outlet end of the blower 31 and the air inlet end (i.e., the air inlet hole 232) of the second passage, that is, the valve member restricts the air flow output by the blower 31 from directly flowing through the valve member to the air inlet hole 232.

[0042] In short, in the first state, under the action of the valve member, the air flow output by the blower 31 is allowed to flow through the valve member to the air inlet 12, and the air flow output by the blower 31 cannot directly flow through the valve member to the air inlet hole 232.

[0043] In the second state, that is Figure 2 In the state shown, the air outlet end of the blower is communicated with the air inlet end (i.e., the air inlet hole 232) of the second passage through the valve member, so as to allow the air flow output by the blower to flow through the valve member to the air inlet hole 232; and, in the second state, the valve member cuts off between the air outlet end of the blower 31 and the air inlet 12 of the furnace chamber, so that the valve member restricts the air flow output by the blower 31 from directly flowing through the valve member to the air inlet 12.

[0044] In short, in the second state, under the action of the valve member, the air flow output by the blower 31 can flow through the valve member to the air inlet hole 232, and the air flow output by the blower cannot directly flow through the valve member to the air inlet 12.

[0045] This embodiment provides a valve member to realize the switching between the above first state and the second state. As Figure 1 shown, the valve member adopts a three-way valve 32, and the three-way valve 32 includes an air inlet valve port 32a, two air outlet valve ports and a valve plate 33.

[0046] Among them, the intake valve port 32a is communicated with the air outlet end of the blower 31; among the two outlet valves, one is communicated with the first pipeline 41, and the other is communicated with the second end of the second pipeline 42 (i.e., the end far from the heat exchanger 2), and the first end of the second pipeline 42 is communicated with the intake hole 232 on the housing 21.

[0047] For the convenience of description, in this embodiment, among the two outlet valves, the one communicated with the first pipeline 41 is denoted as the upper outlet valve port 32b, and the one communicated with the second pipeline 42 is denoted as the lower outlet valve port 32c.

[0048] The valve plate 33 can act between the two outlet valve ports to control the opening / closing of the corresponding outlet valve port so as to realize the switching of the valve member between the first state and the second state. For example, the opening / closing of the corresponding outlet valve port is realized by the rotation of the valve plate 33.

[0049] In the first state, as Figure 1 shown in the state, the valve plate 33 blocks between the intake valve port 32a and the lower outlet valve port 32c to cut off the communication between the intake valve port 32a and the lower outlet valve port 32c, that is, the upper outlet valve port 32b is opened; moreover, in the first state, the intake valve port 32a is communicated with the upper outlet valve port 32b to realize the closing of the lower outlet valve port 32c.

[0050] Thus, after the blower 31 is turned on, as Figure 1 shown by the red arrow part in, the air flow direction is shown. Combining Figure 1 shown, the flow path of the air output by the blower 31 is successively: intake valve port 32a - upper outlet valve port 32b - first pipeline 41 - intake port 12 - furnace chamber 11 - exhaust port 13 - third pipeline 43 - intake chamber 212 - heat exchange tube 22 (i.e., the first channel) - outlet chamber 213 - chimney 5.

[0051] In the second state, as Figure 2 shown, the valve plate 33 blocks between the intake valve port 32a and the upper outlet valve port 32b to cut off the communication between the intake valve port 32a and the upper outlet valve port 32b, that is, the upper outlet valve port 32b is closed, and in the second state, the intake valve port 32a is communicated with the lower outlet valve port 32c to realize the opening of the lower outlet valve port 32c; among them, in Figure 2 shown, the red arrow part indicates the flow path of the high-temperature waste gas output from the exhaust port, and the blue arrow part indicates the flow path of the air output by the blower 31 before entering the furnace chamber 11. Combining Figure 2As shown, after the blower 31 is turned on, the air flow path output by the blower 31 is successively: intake valve port 32a - lower air outlet valve port 32c - second pipeline 42 - intake hole 232 - second channel 23 - air outlet hole 231 - first pipeline 41 - intake port 12 - furnace chamber 11 - exhaust port 13 (discharging high-temperature waste gas) - third pipeline 43 - intake chamber 212 - heat exchange pipe 22 (i.e., the first channel) - air outlet chamber 213 - chimney 5.

[0052] In addition, in some embodiments, a natural gas flow meter is provided at the intake end of the burner 14 for adjusting the amount of natural gas used; and / or an air flow meter is provided at the air outlet end of the blower 31 for adjusting the air volume output by the blower 31.

[0053] In addition, in order to monitor the relevant temperatures during the operation of the system, in some embodiments, a temperature detection component for detecting temperature, such as a temperature sensor, is provided in at least one of the following four parts: inside the furnace chamber 11, between the exhaust port 13 of the furnace chamber 11 and the intake end of the first channel, between the air outlet end of the second channel 23 and the intake port 12 of the furnace chamber 11, and the air outlet end of the first channel.

[0054] Preferably, a first temperature detection component for detecting the temperature inside the furnace chamber 11 is provided inside the furnace chamber 11, a third temperature sensor for detecting the internal temperature of the third pipeline 43 is provided in the third pipeline 43, a second temperature sensor for detecting the internal temperature of the second pipeline 42 is provided in the second pipeline 42, and a fourth temperature sensor for detecting the temperature of the air flow output by the first channel is provided in the air outlet chamber 213 or the chimney 5.

[0055] The operation method of the regenerative combustion system provided in this embodiment specifically includes the following steps: The first step is to preheat the system. The preheating process specifically includes the following steps: First, place the crucible 15 into the furnace chamber 11 before the system starts; Subsequently, switch the valve member to the first state, that is Figure 1 the state shown, so that the air outlet end of the blower 31 is communicated with the intake port 12 of the furnace chamber 11 through the valve member.

[0056] Next, start the blower 31 and turn on the burner 14 for combustion. During this process, the air flow path blown out by the blower 31 is successively: intake valve port 32a - upper air outlet valve port 32b - first pipeline 41 - air inlet 12 - furnace chamber 11 - exhaust port 13 - third pipeline 43 - intake chamber 212 - heat exchange tube 22 (i.e., the first channel) - air outlet chamber 213 - chimney 5. It can be seen that during this process, after the air enters the furnace chamber 11, the heat released by the combustion of natural gas will heat the air inside the furnace chamber 11 to form high-temperature air. The high-temperature air heats the crucible 15 inside the furnace chamber 11, and high-temperature waste gas is discharged from the exhaust port 13 and enters the heat exchange tube 22. During the flow of the high-temperature waste gas in the heat exchange tube 22, it will heat the heat storage medium inside the heat exchange tube 22. At this time, it is equivalent to recovering the waste heat of the waste gas discharged from the furnace chamber 11 through the heat storage medium. The purpose of heating the heat storage medium is to provide a basic temperature for the subsequent formal smelting.

[0057] When the temperature of the heat storage medium reaches the set value, the preheating is completed, and the second step can be carried out. The set value can be 1000 °C. It should be noted that the set value can be adjusted according to the materials to be smelted actually.

[0058] Second step, after the system completes preheating, that is, when the temperature of the heat storage medium reaches the set value, the valve components are switched to the second state for the third step of formal smelting. In the second state, the air outlet end of the blower 31 is connected to the air inlet end (i.e., the air inlet hole 232) of the second channel 23 through the valve components 32; At this time, the air flow path is successively: intake valve port 32a - lower air outlet valve port 32c - second pipeline 42 - air inlet hole 232 - second channel 23 - air outlet hole 231 - first pipeline 41 - air inlet 12 - furnace chamber 11 - exhaust port 13 - third pipeline 43 - intake chamber 212 - heat exchange tube 22 (i.e., the first channel) - air outlet chamber 213 - chimney 5. During this process, when the air passes through the second channel 23, it will exchange heat with the high-temperature heat storage medium inside the heat exchange tube 22, so that the air is heated to form high-temperature air. The high-temperature air then enters the furnace chamber 11 through the first pipeline 41 and fully burns with natural gas to form waste gas. The waste gas still has a relatively high temperature, that is, high-temperature waste gas. The high-temperature waste gas flows back through the third pipeline 43 and passes through the heat exchange tube 22 again to heat the heat storage medium inside the heat exchange tube 22 and exchange heat with the air sent into the second channel 23 by the blower 31. Finally, the high-temperature waste gas is cooled, and the cooled waste gas is finally discharged by the chimney 5.

[0059] Third step, put the material to be smelted into the crucible inside the furnace chamber for smelting; when the material in the crucible reaches the set value, take out the crucible and pour out the smelted material. If there is still material to be smelted at this time, after the smelted material is poured out of the crucible, put the crucible into the furnace chamber again, and continue to put the material to be smelted into the crucible inside the furnace chamber for continuous smelting.

[0060] It should be noted that the reason for preheating the system in this application is as follows. Firstly, preheating the system can preheat the crucible 15 in the furnace chamber 11 and dry to reduce the moisture in the furnace chamber 11. During the preheating process, the high-temperature exhaust gas (i.e., the air discharged from the exhaust port 13) will flow into the heat exchange tube 22 to heat the heat storage medium, so as to recover the waste heat in the exhaust gas and achieve the purpose of energy conservation. Moreover, when the heat storage medium absorbs the heat of the exhaust gas, the temperature of the exhaust gas will also be correspondingly reduced, so that the temperature of the finally discharged exhaust gas will not be too high.

[0061] In this application, the heat absorbed by the heat storage medium during the system preheating stage can be utilized subsequently in the formal smelting step, that is, used to heat the air output by the blower 31, so that the air entering the furnace chamber 11 becomes high-temperature air to fully burn with natural gas and achieve dispersed combustion.

[0062] It can be seen that in this application, not only can the waste heat of the exhaust gas be recovered through the heat storage medium, but also the recovered waste heat can be fed back to the system to generate high-temperature air to enter the furnace chamber 11 to assist in burning natural gas and achieve dispersed combustion.

[0063] The reason for initially heating the temperature of the heat storage medium to the set value is to ensure that the temperature of the air entering the furnace chamber 11 is high enough during the subsequent formal smelting. In other words, if the heat storage medium is not heated initially but the formal smelting work is carried out at room temperature, then, in the heat exchange process of the heat exchanger 2, without considering heat loss, part of the heat released by the exhaust gas will heat the air in the second channel 23, and part will heat the heat storage medium. That is to say, part of the heat released by the exhaust gas will be absorbed by the heat storage medium at a lower temperature, making it difficult to heat the air in the second channel 23 to a very high temperature, and thus the effect of dispersed combustion cannot be achieved.

[0064] In this application, since the heat storage medium has been heated to a relatively high temperature during the preheating stage, when the high-temperature exhaust gas discharged subsequently is in the heat exchanger 2 during the formal smelting, most of its heat will be transferred to the air in the second channel 23, so that the air is heated to a sufficient temperature. Generally speaking, the temperature of the air entering the furnace chamber 11 is basically close to the temperature of the heat storage medium. That is to say, during the formal smelting stage, high-temperature air with sufficient temperature can always enter the furnace chamber 11 without the need to switch the valve parts again.

[0065] Equivalently, this application only needs to perform a valve part switching operation once to achieve dispersed combustion. Compared with the existing method that requires multiple valve switchings, the operation is more convenient and can effectively reduce the problems of furnace temperature fluctuation and flameout caused by frequent valve switching.

[0066] Moreover, in the present application, the waste heat of the exhaust gas in the combustion process is effectively recycled, achieving the purpose of energy conservation.

[0067] In addition, in this embodiment, during the entire smelting process, the blower 31 is basically not in contact with high-temperature air, and the high-temperature air does not directly pass through the valve components, thus reducing the risk of damage to the blower 31 and the valve components due to high temperature.

[0068] Furthermore, for the valve components in the present application, they can be either manually controlled or automatically controlled. For example, the system includes a controller and a temperature sensor for detecting the temperature of the heat storage medium, and the valve components are solenoid valves controlled by the controller. The controller is configured to, when the temperature value detected by the temperature sensor reaches the set value, control the valve components to act, causing the valve components to switch from the first state to the second state.

[0069] Embodiment 2 Combined with Figure 3 As shown, this embodiment is basically the same as Embodiment 1, except that the valve components used in the two are different. For example, in Embodiment 1, the valve components are implemented by a three-way valve 32.

[0070] In this embodiment, the valve components use two valves. The second ends of the first pipeline 41 and the second pipeline 42 are connected through a connecting pipe 6, that is, one end of the connecting pipe 6 is connected to the first pipeline 41, and the other end is connected to the second end of the second pipeline 42; the two valves are arranged on the connecting pipe 6 at intervals, that is, the two valves are connected in series on the connecting pipe 6; and the position of the connecting pipe 6 between the two valves is connected to the air outlet end of the blower 31.

[0071] In this way, only two valves need to be controlled to make the valve components enter the first state and the second state. Specifically: for the convenience of description, in this embodiment, the valve located on the upper side is denoted as the upper valve 61, and the valve located on the lower side is denoted as the lower valve 62; when the upper valve 61 is closed and the lower valve 62 is open, the valve components are equivalent to being in the second state; when the upper valve 61 is open and the lower valve 62 is closed, the valve components are equivalent to being in the first state.

[0072] It should be understood that various forms of the processes shown above can be used, reordering, adding, or deleting steps. For example, the steps described in the present application can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present application can be achieved, and no limitations are imposed herein.

[0073] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, "a plurality" means two or more unless otherwise specifically defined.

[0074] As described above, the above are only specific embodiments of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed in this application can easily think of changes or substitutions, which should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claimed rights.

Claims

1. A regenerative combustion system, characterized in that, Comprising: A smelting furnace, within which there is a hearth; the hearth includes an air inlet and an exhaust outlet, and a burner is provided on the smelting furnace; A heat exchanger, which includes a first channel and a second channel that are in air flow communication and can exchange heat with each other; a heat storage medium capable of storing heat is provided in the first channel; the exhaust outlet of the hearth is communicated with the inlet end of the first channel; the air inlet of the hearth is communicated with the outlet end of the second channel; A blowing mechanism, including a blower and a valve member, the air inlet of the hearth and the inlet end of the second channel are connected to the outlet end of the blower through the valve member, and the valve member can switch between a first state and a second state to switch the air flow direction of the blower; In the first state, the outlet end of the blower is communicated with the air inlet of the hearth through the valve member, and the valve member cuts off between the outlet end of the blower and the inlet end of the second channel; In the second state, the valve member cuts off between the outlet end of the blower and the air inlet of the hearth, and the outlet end of the blower is communicated with the inlet end of the second channel through the valve member.

2. The regenerative combustion system according to claim 1, wherein The system further includes a pipeline assembly; the pipeline assembly includes a first pipeline and a second pipeline; The first end of the first pipeline is communicated with the outlet end of the second channel, and the second end of the first pipeline is communicated with the air inlet of the hearth; the first pipeline is also connected to the outlet end of the blower through a valve member; The first end of the second pipeline is communicated with the inlet end of the second channel; the second end of the second pipeline is connected to the outlet end of the blower through a valve member.

3. The regenerative combustion system according to claim 2, characterized in that, The valve member includes a three-way valve, the three-way valve includes an inlet valve port, two outlet valve ports and a valve plate; the inlet valve port is communicated with the outlet end of the blower; among the two outlet valve ports, one is communicated with the first pipeline, and the other is communicated with the second end of the second pipeline; the valve plate can act between the two outlet valve ports to control the opening / closing of the corresponding outlet valve port.

4. The regenerative combustion system according to claim 2, characterized in that, The valve member includes two valves, the second ends of the first pipeline and the second pipeline are communicated through a connecting pipe, and the two valves are arranged on the connecting pipe at intervals; the position of the connecting pipe between the two valves is communicated with the outlet end of the blower.

5. A regenerative combustion system according to claim 1, wherein The heat exchanger is a shell-and-tube heat exchanger, which includes a shell and heat exchange tubes; the internal space of the shell includes a heat exchange chamber and an inlet chamber and an outlet chamber respectively located at both ends of the heat exchange chamber, and the inlet chamber is communicated with the exhaust outlet of the hearth; the heat exchange tubes are arranged in the heat exchange chamber and are respectively communicated with the inlet chamber and the outlet chamber at both ends; the heat storage medium is arranged in the heat exchange tubes.

6. A regenerative combustion system according to claim 1, wherein, The heat storage medium is at least one of alumina balls, silicon carbide balls, and zirconia balls.

7. A regenerative combustion system according to claim 1, characterized in that, The system further includes a chimney, and the chimney is communicated with the outlet end of the first channel.

8. A regenerative combustion system according to claim 1, wherein A natural gas flowmeter is provided at the inlet end of the burner for adjusting the consumption of natural gas; and / or an air flowmeter is provided at the outlet end of the blower for adjusting the air volume output by the blower.

9. A regenerative combustion system according to claim 1, wherein A temperature detection member for detecting temperature is provided in at least one of the following four: inside the hearth, between the exhaust outlet of the hearth and the inlet end of the first channel, between the outlet end of the second channel and the air inlet of the hearth, and the outlet end of the first channel.

10. A method for operating a regenerative combustion system, characterized in that, The operation method is applied to the regenerative combustion system according to any one of claims 1-9, and the operation method includes the following steps: S1. System preheating, including the following steps: S11. Place the crucible in the furnace before starting the system; S12. Switch the valve to the first state; S13. Start the blower and turn on the burner for combustion. The hot air in the furnace flows through the exhaust port and through the first channel to heat the heat storage medium in the first channel; S2. When the temperature of the heat storage medium reaches the set value, switch the valve to the second state; S3. Put the material to be melted into the crucible in the furnace; S4. When the temperature of the material in the crucible reaches the set value, take out the crucible and pour out the melted material.

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