A regenerative combustion system and method of operation thereof

Abstract

The application relates to the field of combustion smelting systems, in particular to a heat accumulation combustion system and a running method thereof. The system comprises a smelting furnace, the smelting furnace is internally provided with a hearth; a burner is arranged on the smelting furnace; a heat exchanger comprises a first channel and a second channel; a heat accumulation medium capable of accumulating heat is arranged in the first channel; an air inlet of the hearth is communicated with an air outlet end of the second channel; an air blower mechanism comprises an air blower and a valve; the valve comprises a first state and a second state; in the first state, an air outlet end of the air blower is communicated with the air inlet of the hearth through the valve, and the valve is cut off between the air outlet end of the air blower and an air inlet end of the second channel; in the second state, the valve 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; the scheme can not only recycle and utilize the waste heat of high-temperature exhaust gas generated by combustion, so as to achieve the purpose of energy saving, but also does not need to frequently switch the valve.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of combustion smelting system, and in particular to a regenerative combustion system and a method for operating the same. BACKGROUND

[0002] Smelting is the first process of metal processing in smelting industry, and the main production process is: raw materials (aluminum ingots, iron ingots, etc.) → smelting furnace → holding furnace → online degassing device → filter box → liquid level control flow divider → casting machine → finished product. The main equipment includes smelting furnace, holding furnace and casting machine, etc. Among them, the smelting furnace is an essential equipment for smelting plant, and its main function is to provide qualified metal liquid to the casting machine.

[0003] In the combustion system composed of the smelting furnace, with the progress of science and technology, the reversing combustion technology and the regenerative technology are combined in industry, and the “dispersion combustion technology” (also known as regenerative high-temperature air combustion technology) is developed and popularized. Compared with the traditional combustion technology, the dispersion combustion technology not only saves fuel, but also has lower NOx emission. X

[0004] In order to realize the dispersion combustion, in some related technologies, two regenerative chambers are used, and a switching valve is used to switch the flue gas and air back and forth, which can be specifically referred to the technologies disclosed in the patent documents with the application numbers of 201821772403.8, 201310101708.1 and 201020661098.2.

[0005] The disadvantage of this way is that there is a problem of non-steady state and intermittent combustion operation, which is easy to cause fluctuation of furnace temperature and flameout; the switching valve is switched frequently, which increases the failure rate and gas leakage risk, and increases the operation and maintenance cost.

[0006] For example, the application number 202010963357.5 discloses a dispersion type regenerative aluminum smelting furnace, which heats the combustion-supporting air through a pipeline system to reach the required combustion-supporting air temperature for dispersion combustion, and can achieve continuous and stable dispersion combustion state. The heat for heating the combustion-supporting air is directly absorbed and released by the regenerative heat exchanger arranged on the side of the smelting mechanism, instead of recovering the waste heat of the discharged flue gas, so that energy saving is not achieved. SUMMARY

[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 a method for operating the same.

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

[0009] On the one hand, the present application provides a regenerative combustion system, comprising:

[0010] ​The smelting furnace is internally provided with a hearth; the hearth comprises an air inlet and an air outlet, and the smelting furnace is provided with a burner;

[0011] The heat exchanger comprises a first channel and a second channel which are in communication with each other and capable of exchanging heat with each other; the first channel is internally provided with heat storage medium capable of storing heat; the air outlet of the hearth is in communication with the air inlet end of the first channel; the air inlet of the hearth is in communication with the air outlet end of the second channel;

[0012] The air blower mechanism comprises an air blower and a valve; the air inlet of the hearth and the air inlet end of the second channel are connected to the air outlet end of the air blower through the valve; the valve is capable of switching between a first state and a second state to switch the air outlet direction of the air blower;

[0013] In the first state, the air outlet end of the air blower is in communication with the air inlet of the hearth through the valve, and the valve is cut off between the air outlet end of the air blower and the air inlet end of the second channel;

[0014] In the second state, the valve 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 in communication with the air inlet end of the second channel through the valve.

[0015] As an optional embodiment of the present application, the system further comprises a pipeline assembly; the pipeline assembly comprises a first pipeline and a second pipeline;

[0016] The first end of the first pipeline is in communication with the air outlet end of the second channel, and the second end of the first pipeline is in communication with the air inlet of the hearth; the first pipeline is further connected to the air outlet end of the air blower through the valve;

[0017] The first end of the second pipeline is in communication with the air inlet end of the second channel; the second end of the second pipeline is connected to the air outlet end of the air blower through the valve.

[0018] As an optional embodiment of the present application, the valve comprises a three-way valve, the three-way valve comprises an air inlet valve port, two air outlet valve ports and a valve plate; the air inlet valve port is in communication with the air outlet end of the air blower; one of the two air outlet valve ports is in communication with the first pipeline, and the other is in communication with the second end of the second pipeline; the valve plate is capable of moving between the two air outlet valve ports to control the opening / closing of the corresponding air outlet valve port.

[0019] As an optional embodiment of the present application, the valve comprises two valves, the second ends of the first pipeline and the second pipeline are connected through a communication pipe, and the two valves are arranged on the communication pipe at intervals; the position of the communication pipe between the two valves is in communication with the air outlet end of the air blower.

[0020] As an optional embodiment of the present application, the heat exchanger is a shell-and-tube heat exchanger, which comprises a shell and heat exchange tubes; the internal space of the shell comprises a heat exchange chamber and an air inlet chamber and an air outlet chamber respectively located at two ends of the heat exchange chamber, the air inlet chamber is connected with the exhaust port of the furnace chamber; the heat exchange tubes are arranged in the heat exchange chamber and are connected with the air inlet chamber and the air outlet chamber respectively; the heat storage medium is arranged in the heat exchange tubes.

[0021] As an optional embodiment of the present application, the heat storage medium is at least one of alumina balls, silicon carbide balls and zirconia balls.

[0022] As an optional embodiment of the present application, the system further comprises a chimney, which is connected with the air outlet end of the first channel.

[0023] As an optional embodiment of the present application, the air end is provided with a natural gas flow meter for adjusting the amount of natural gas; and / or the air outlet end of the air blower is provided with an air flow meter for adjusting the air volume output by the air blower.

[0024] As an optional embodiment of the present application, at least one of the following is provided with a temperature detection member for detecting temperature: the furnace chamber, the space between the exhaust port of the furnace chamber and the air inlet end of the first channel, the space between the air outlet end of the second channel and the air inlet port of the furnace chamber, and the air outlet end of the first channel.

[0025] In another aspect, the present application also provides a running method of a heat storage combustion system, which is applied to the heat storage combustion system described above, and the running method comprises the following steps:

[0026] S1, system preheating, comprising the following steps:

[0027] S11, placing the crucible in the furnace chamber before starting the system;

[0028] S12, switching the valve to the first state;

[0029] S13, starting the air blower and opening the burner to carry out combustion, and the hot air in the furnace chamber flows through the first channel through the exhaust port to heat the heat storage medium in the first channel;

[0030] S2, when the temperature of the heat storage medium reaches a set value, the valve is switched to the second state;

[0031] S3, placing the material to be smelted into the crucible in the furnace chamber;

[0032] S4, when the temperature of the material in the crucible reaches a set value, taking out the crucible and pouring out the smelted material.

[0033] Compared with the prior art, the present application has the following beneficial effects:

[0034] Firstly, in actual operation, by preheating the furnace, the furnace interior can be dried and the crucible inside the furnace can be preliminarily heated, and the high-temperature waste gas generated in the preheating process can be recovered by the heat storage medium to heat the heat storage medium to a set temperature value, and the heat recovered by the heat storage medium can be used in the subsequent smelting process to heat the air output by the air blower to become high-temperature air, which can assist the combustion of natural gas and realize diffuse combustion.

[0035] Secondly, only one switching operation of the valve is needed to realize diffuse combustion, which is simpler than the existing way of switching valves multiple times, and can effectively reduce the problems of furnace temperature fluctuation and flameout caused by frequent switching of valves.

[0036] Moreover, in the present application, the waste heat in the combustion process is effectively recycled, achieving the purpose of energy saving.

[0037] 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 intended to limit the scope of the present application. Other features of the present application will become apparent through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0038] The above and other objects, features and advantages of the exemplary embodiments of the present application will be more apparent from the following detailed description taken in conjunction with the accompanying drawings. In the drawings, several embodiments of the present application are shown by way of example and not limitation, in which:

[0039] In the drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0040] Figure 1 A structural schematic diagram of the embodiment 1 of the present application (valve in the first state) is shown;

[0041] Figure 2 A structural schematic diagram of the embodiment 1 of the present application (valve in the second state) is shown;

[0042] Figure 3 A structural schematic diagram of the embodiment 2 of the present application is shown.

[0043] Explanation of reference numerals in the drawings:

[0044] 1, smelting furnace; 11, furnace; 12, air inlet; 13, air outlet; 14, burner; 15, crucible;

[0045] 2, heat exchanger; 21, shell; 211, heat exchange chamber, 212, air inlet chamber; 213, air outlet chamber; 22, heat exchange pipe; 23, second channel; 231, air outlet hole; 232, air inlet hole;

[0046] 3, blower mechanism; 31, blower; 32, three-way valve; 32a, air inlet port; 32b, upper air outlet port; 32c, lower air outlet port; 33, valve plate;

[0047] 4, pipeline assembly; 41, first pipeline; 42, second pipeline; 43, third pipeline;

[0048] 5, chimney;

[0049] 6, communication pipe; 51, upper valve; 52, lower valve. DETAILED DESCRIPTION

[0050] In order to make the purpose, features and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the 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 labor fall within the scope of protection of the present application.

[0051] Embodiment 1

[0052] As shown in Figure 1 and Figure 2 , the present embodiment provides a regenerative combustion system, mainly used for smelting or melting of materials (such as aluminum ingots, iron ingots); the system mainly adopts dispersion combustion technology (also known as regenerative high-temperature air combustion technology).

[0053] The system mainly includes a smelting furnace 1, a heat exchanger 2, a blower mechanism 3, a pipeline assembly 4, a chimney 5, etc., and the components will be described in detail below.

[0054] As shown in Figure 1 , the smelting furnace 1 is provided with a hearth 11, and the material to be smelted is generally loaded in a crucible 15, and then the crucible 15 is placed in the hearth 11 for high-temperature smelting.

[0055] Among them, the hearth 11 includes an air inlet 12 and an air outlet 13, in some embodiments, the air inlet 12 and the air outlet 13 are both provided on the side wall of the smelting furnace 1 and both communicate with the hearth 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 hearth 11 from the air inlet 12, and high-temperature waste gas generated by high-temperature combustion in the hearth 11 is discharged from the air outlet 13.

[0056] The heat exchanger 2 includes a first passage and a second passage 23 in communication with the gas flow and capable of heat exchange with each other; the first passage and the second passage 23 both have an air inlet end and an air outlet end, and the gas flow enters from the air inlet end and is discharged from the air outlet end.

[0057] The first channel is equipped with a heat storage medium capable of storing heat. The heat storage medium can be one or more of alumina balls, silicon carbide balls, and zirconia balls, and the size of the alumina balls, silicon carbide balls, and zirconia balls is 5mm to 20mm.

[0058] In some embodiments, heat exchanger 2 is preferably a shell-and-tube heat exchanger, specifically constructed as follows:

[0059] like Figure 1 As shown, the heat exchanger 2 includes a shell 21 and heat exchange tubes 22; the shell 21 forms a closed internal space, which is vertically divided into a heat exchange chamber 211 and an air inlet chamber 212 and an air outlet chamber 213 located at both ends of the heat exchange chamber 211, respectively. Specifically, in this embodiment, as... Figure 1 From the view shown, 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.

[0060] The heat exchange tubes 22 comprise several tubes, each arranged vertically within the heat exchange chamber 211. One end of each heat exchange tube 22 is connected to the inlet chamber 212, and the other end is connected to the outlet chamber 213. In this configuration, each heat exchange tube 22 forms a first channel, with the inlet chamber 212 forming the inlet end and the outlet chamber 213 forming the outlet end. The heat storage medium is filled within the heat exchange tubes 22.

[0061] Inside 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 the second channel 23. Thus, an air outlet 231 is opened on the upper part of the side wall of the shell 21 as the air outlet of the second channel 23, and an air inlet 232 is opened on the lower part of the side wall of the shell 21 as the air inlet of the second channel 23.

[0062] In this way, the airflow flowing in the first channel (i.e., heat exchange tube 22) and the airflow flowing in the second channel 23 will exchange heat through the heat exchange tube 22.

[0063] In this embodiment, as Figure 1 As shown, the conduit assembly 4 is mainly used to realize the connection between various ports. Specifically, the conduit assembly 4 includes a first conduit 41, a second conduit 42, a third conduit 43, etc. The following is a detailed description of each specific structure.

[0064] The exhaust port 13 of the furnace 11 is connected to the air inlet of the first channel via a third pipe 43, that is, one end of the third pipe 43 is connected to the exhaust port 13, and the other end is connected to the air inlet chamber 212; the exhaust chamber 213 is connected to the chimney 5; thus, Figure 1The red arrow in the middle indicates the preheating stage. The airflow path is as follows: the high-temperature exhaust gas generated by combustion in the furnace 11 flows through the exhaust port 13, then through the third pipe 43, the air inlet chamber 212, the heat exchange tube 22, and the air outlet chamber 213, and is finally discharged from the chimney 5.

[0065] The air inlet 12 of the furnace 11 is connected to the air outlet of the second channel 23 through the first pipe 41, that is, the first end of the first pipe 41 is connected to the air outlet 231 on the side wall of the shell 21, and the second end of the first pipe 41 is connected to the air inlet 12 of the furnace 11.

[0066] The blower mechanism 3 is mainly used to blow air into the furnace 11 to assist combustion; the blower mechanism 3 includes a blower 31 and valves.

[0067] The air inlet 12 of the furnace 11 and the air inlet end (i.e., air inlet hole 232) of the second channel 23 are connected to the air outlet end of the blower 31 through a valve. The valve can switch between a first state and a second state to switch the air outlet direction of the blower 31.

[0068] In the first state, that is Figure 1 As shown, in the first state, the air outlet of the blower 31 is connected to the air inlet 12 of the furnace 11 through a valve, so that the airflow output by the blower 31 can flow to the air inlet 12 through the valve; and, in the first state, the valve is also cut off between the air outlet of the blower 31 and the air inlet of the second channel (i.e., the air inlet 232), that is, the valve restricts the airflow output by the blower 31 from flowing directly to the air inlet 232 through the valve.

[0069] In short, in the first state, under the action of the valve, the airflow output by the blower 31 is allowed to flow to the air inlet 12 through the valve, and the airflow output by the blower 31 cannot flow directly to the air inlet 232 through the valve.

[0070] In the second state, that is Figure 2 In the indicated state, the air outlet of the blower is connected to the air inlet of the second channel (i.e., air inlet 232) through a valve, so as to allow the airflow output by the blower to flow to the air inlet 232 through the valve; and in the second state, the valve cuts off the air outlet of the blower 31 and the air inlet 12 of the furnace, so as to restrict the airflow output by the blower 31 from flowing directly to the air inlet 12 through the valve.

[0071] In short, in the second state, under the action of the valve, the airflow output by the blower 31 can flow to the air inlet 232 through the valve, and the airflow output by the blower cannot flow directly to the air inlet 12 through the valve.

[0072] This embodiment provides a valve to achieve the switching between the first state and the second state described above, such as...Figure 1 As shown, the valve piece adopts a three-way valve 32, which includes one air inlet valve port 32a and two air outlet valve ports as well as a valve plate 33.

[0073] The air inlet valve port 32a is in communication with the air outlet end of the blower 31; one of the two air outlet valve ports is in communication with the first pipeline 41, and the other is in communication with the second end of the second pipeline 42 (i.e. the end away from the heat exchanger 2), and the first end of the second pipeline 42 is in communication with the air inlet hole 232 on the shell 21.

[0074] For the convenience of description, in the embodiment, one of the two air outlet valve ports in communication with the first pipeline 41 is denoted as the upper air outlet valve port 32b, and the other in communication with the second pipeline 42 is denoted as the lower air outlet valve port 32c.

[0075] The valve plate 33 can act between the two air outlet valve ports to control the opening / closing of the corresponding air outlet valve port to realize the switching of the valve piece between the first state and the second state, for example, by rotating the valve plate 33 to realize the opening / closing of the corresponding air outlet valve port.

[0076] In the first state, as shown in the state, Figure 1 the valve plate 33 blocks between the air inlet valve port 32a and the lower air outlet valve port 32c to cut off the communication between the air inlet valve port 32a and the lower air outlet valve port 32c, i.e. the upper air outlet valve port 32b is open; and in the first state, the air inlet valve port 32a is in communication with the upper air outlet valve port 32b to realize the closing of the lower air outlet valve port 32c.

[0077] Thus, after the blower 31 is turned on, as shown in the red arrow part in the figure, Figure 1 in combination with the figure, Figure 1 the flow path of the air output by the blower 31 is: air inlet valve port 32a-upper air outlet valve port 32b-first pipeline 41-air inlet 12-furnace 11-exhaust port 13-third pipeline 43-air inlet chamber 212-heat exchange pipe 22 (i.e. first passage)-air outlet chamber 213-chimney 5.

[0078] In the second state, as shown in the state, Figure 2 the valve plate 33 blocks between the air inlet valve port 32a and the upper air outlet valve port 32b to cut off the communication between the air inlet valve port 32a and the upper air outlet valve port 32b, i.e. the upper air outlet valve port 32b is closed, and in the second state, the air inlet valve port 32a and the lower air outlet valve port 32c are in communication to realize the opening of the lower air outlet valve port 32c; wherein, Figure 2 in the figure, the red arrow part indicates the flow path of the high-temperature exhaust gas output by the exhaust port, and the blue arrow part indicates the flow path of the air output by the blower 31 before entering the furnace 11, in combination with the figure, Figure 2As shown, after the blower 31 is turned on, the air flow path of the air output by the blower 31 is: the air inlet valve port 32a - the lower air outlet valve port 32c - the second pipeline 42 - the air inlet hole 232 - the second passage 23 - the air outlet hole 231 - the first pipeline 41 - the air inlet port 12 - the furnace 11 - the air outlet port 13 (for discharging high-temperature exhaust gas) - the third pipeline 43 - the air inlet chamber 212 - the heat exchange pipe 22 (i.e., the first passage) - the air outlet chamber 213 - the chimney 5.

[0079] In addition, in some embodiments, the air inlet end of the burner 14 is provided with a natural gas flow meter for adjusting the amount of natural gas; and / or the air outlet end of the blower 31 is provided with an air flow meter for adjusting the amount of air output by the blower 31.

[0080] In addition, in order to monitor the relevant temperatures during the operation of the system, in some embodiments, at least one of the following is provided with a temperature detection member, such as a temperature sensor, for detecting the temperature: the furnace 11, the space between the air outlet port 13 of the furnace 11 and the air inlet end of the first passage, the space between the air outlet end of the second passage 23 and the air inlet port 12 of the furnace 11, and the air outlet end of the first passage.

[0081] Preferably, the furnace 11 is provided with a first temperature detection member for detecting the temperature in the furnace 11, the third pipeline 43 is provided with a third temperature sensor for detecting the temperature inside the third pipeline 43, the second pipeline 42 is provided with a second temperature sensor for detecting the temperature inside the second pipeline 42, and the air outlet chamber 213 or the chimney 5 is provided with a fourth temperature sensor for detecting the temperature of the air flow output by the first passage.

[0082] The operation method of the regenerative combustion system provided by the embodiment specifically includes the following steps:

[0083] First, preheating the system, and the preheating process specifically includes the following steps:

[0084] First, before starting the system, the crucible 15 is placed in the furnace 11.

[0085] Subsequently, the valve member is switched to the first state, i.e. Figure 1 As shown, the air outlet end of the blower 31 is in communication with the air inlet port 12 of the furnace 11 through the valve member.

[0086] Next, the air blower 31 is started, and the burner 14 is turned on to burn, in the process, the air flow path of the air blower 31 is: the air inlet valve port 32a - the upper air outlet valve port 32b - the first pipeline 41 - the air inlet 12 - the furnace 11 - the air outlet 13 - the third pipeline 43 - the air inlet chamber 212 - the heat exchange pipe 22 (i.e. the first passage) - the air outlet chamber 213 - the chimney 5. It can be seen that in the process, after the air enters the furnace 11, the heat released by the natural gas combustion heats the air inside the furnace 11, forming high-temperature air, which heats the crucible 15 in the furnace 11 and discharges high-temperature waste gas from the air outlet 13 into the heat exchange pipe 22. The high-temperature waste gas flows in the heat exchange pipe 22 and heats the heat storage medium in the heat exchange pipe 22. At this time, the waste heat of the exhaust gas discharged from the furnace 11 is recovered through the heat storage medium. The purpose of heating the heat storage medium is to provide a basic temperature for subsequent formal smelting.

[0087] When the temperature of the heat storage medium reaches the set value, the preheating is completed, and the second step can be performed. The set value can be 1000℃. It should be noted that the set value can be adjusted according to the actual smelting material.

[0088] The second step, after the system completes the preheating, i.e. when the temperature of the heat storage medium reaches the set value, the valve switches to the second state for the third step of formal smelting. In the second state, the air outlet end of the air blower 31 is connected to the air inlet end (i.e. the air inlet hole 232) of the second passage 23 through the valve 32.

[0089] At this time, the air flow path is: the air inlet valve port 32a - the lower air outlet valve port 32c - the second pipeline 42 - the air inlet hole 232 - the second passage 23 - the air outlet hole 231 - the first pipeline 41 - the air inlet 12 - the furnace 11 - the air outlet 13 - the third pipeline 43 - the air inlet chamber 212 - the heat exchange pipe 22 (i.e. the first passage) - the air outlet chamber 213 - the chimney 5. In the process, the air exchanges heat with the high-temperature heat storage medium in the heat exchange pipe 22 when it passes through the second passage 23, so that the air is heated to form high-temperature air. The high-temperature air enters the furnace 11 through the first pipeline 41 and fully burns with the natural gas to form waste gas, which still has a high temperature, i.e. high-temperature waste gas. The high-temperature waste gas flows back through the heat exchange pipe 22 again to heat the heat storage medium in the heat exchange pipe 22 and exchange heat with the air sent into the second passage 23 by the air blower 31. Finally, the high-temperature waste gas is cooled, and the cooled waste gas is finally discharged from the chimney 5.

[0090] The third step is to put the material to be smelted into the crucible in the furnace for smelting. When the material in the crucible reaches the set value, the crucible is taken out and the smelted material is poured out. If there is still material to be smelted at this time, after the crucible is poured out, the crucible is put into the furnace again, and the material to be smelted is put into the crucible in the furnace for continuous smelting.

[0091] It is worth mentioning that the system is preheated first, which means that the crucible 15 in the furnace 11 is preheated and dried to reduce the humidity in the furnace 11. During the preheating process, the high-temperature exhaust gas (i.e. the air discharged from the exhaust port 13) flows into the heat exchange pipe 22 to heat the heat storage medium. In this way, the waste heat in the exhaust gas is recovered to achieve the purpose of energy saving. Moreover, when the heat storage medium absorbs the heat of the exhaust gas, the temperature of the exhaust gas is also reduced accordingly, so that the final exhaust temperature is not too high.

[0092] In this application, the heat absorbed by the heat storage medium during the preheating stage of the system can be utilized in the subsequent formal smelting step, i.e. used to heat the air output by the air blower 31, so that the air entering the furnace 11 becomes high-temperature air to fully burn the natural gas and achieve diffuse combustion.

[0093] As can be seen, in this application, not only can the waste heat be recovered, but also the recovered waste heat can be fed back to the system to produce high-temperature air to assist in the combustion of natural gas in the furnace 11 to achieve diffuse combustion.

[0094] The purpose of heating the temperature of the heat storage medium to a set value at the beginning is to ensure that the air temperature entering the furnace 11 is high enough during the formal smelting process. In other words, if the heat storage medium is not heated at the beginning and is used in the formal smelting process at room temperature, without considering heat loss, part of the heat released by the exhaust gas will heat the air in the second channel 23, and the other part will heat the heat storage medium. That is, part of the heat released by the exhaust gas will be absorbed by the heat storage medium with 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 diffuse combustion cannot be achieved.

[0095] In this application, since the heat storage medium has been heated to a relatively high temperature during the preheating stage, most of the heat of the high-temperature exhaust gas will be transferred to the air in the second channel 23 when it is in the heat exchanger 2 during the formal smelting process, so that the air is heated to a sufficient temperature. Generally, the temperature of the air entering the furnace 11 is basically similar to the temperature of the heat storage medium. That is, during the formal smelting stage, high-temperature air with sufficient temperature can always enter the furnace 11, and there is no need to switch the valve again.

[0096] In other words, only one switching operation of the valve is required in this application to achieve diffuse combustion. Compared with the existing method of switching the valve multiple times, the operation is more simple and convenient, and the problem of temperature fluctuation and extinguishing caused by frequent switching of the valve can be effectively reduced.

[0097] Moreover, in the present application, the waste heat of the exhaust gas in the combustion process is effectively recycled, achieving the purpose of energy saving.

[0098] In addition, in the present embodiment, the blower 31 is not in contact with the high-temperature air during the entire smelting process, and the high-temperature air does not directly pass through the valve, thereby reducing the risk of damage to the blower 31 and the valve due to high temperature.

[0099] In addition, the valve in the present application can be 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 is an electromagnetic valve controlled by the controller. The controller is configured to control the valve to switch from the first state to the second state when the temperature detected by the temperature sensor reaches a set value.

[0100] Embodiment 2

[0101] In combination Figure 3 The present embodiment is basically the same as embodiment 1, the difference is only that the valves used in the two embodiments are different. For example, in embodiment 1, the valve is realized by a three-way valve 32.

[0102] In the present embodiment, the valve uses two valves, the second ends of the first pipeline 41 and the second pipeline 42 are connected through a communication pipe 6, that is, one end of the communication pipe 6 is connected with the first pipeline 41, and the other end is connected with the second end of the second pipeline 42; the two valves are arranged at intervals on the communication pipe 6, that is, the two valves are connected in series on the communication pipe 6; and the position of the communication pipe 6 between the two valves is connected with the air outlet end of the blower 31.

[0103] In this way, only two valves need to be controlled to control the valve to enter the first state and the second state. Specifically, in order to facilitate the description, the valve on the upper side is referred to as the upper valve 61, and the valve on the lower side is referred to as the lower valve 62; when the upper valve 61 is closed and the lower valve 62 is opened, the valve is equivalent to being in the second state; when the upper valve 61 is opened and the lower valve 62 is closed, the valve is equivalent to being in the first state.

[0104] It should be understood that various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present application can be executed in parallel, sequentially or in different order, as long as the desired results of the technical solutions disclosed in the present application can be achieved, which is not limited herein.

[0105] In addition, the terms "first", "second", etc. are used only for the purpose of description, and should not be understood as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0106] The above description is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of operating a regenerative combustion system, characterized by, The operation method is applied to a heat accumulation combustion system, and the heat accumulation combustion system comprises: a smelting furnace, which is internally provided with a hearth; the hearth comprises an air inlet and an air outlet, and the smelting furnace is provided with a burner; a heat exchanger, which comprises a first channel and a second channel that are in communication with each other and can exchange heat with each other; the first channel is internally provided with heat accumulation medium that can accumulate heat; the air outlet of the hearth is in communication with an air inlet end of the first channel; the air inlet of the hearth is in communication with an air outlet end of the second channel; the heat exchanger is a tubular heat exchanger, which comprises a shell and a heat exchange tube; the internal space of the shell comprises a heat exchange chamber and an air inlet chamber and an air outlet chamber that are respectively located at two ends of the heat exchange chamber; the air inlet chamber is in communication with the air outlet of the hearth; the heat exchange tube is arranged in the heat exchange chamber and is in communication with the air inlet chamber and the air outlet chamber at two ends thereof; the heat accumulation medium is arranged in the heat exchange tube; the heat exchange tube constitutes the first channel, the air inlet chamber constitutes the air inlet end of the first channel, and the air outlet chamber constitutes the air outlet end of the first channel; in the heat exchange chamber, gaps between the heat exchange tubes and gaps between the heat exchange tube and the inner wall of the shell constitute the second channel; an air outlet hole is arranged at the upper part of the side wall of the shell as the air outlet end of the second channel, and an air inlet hole is arranged at the lower part of the side wall of the shell as the air inlet end of the second channel; an air blower mechanism, which comprises an air blower and a valve; the air inlet of the hearth and the air inlet end of the second channel are connected to the air outlet end of the air blower through the valve; the valve can be switched between a first state and a second state to switch the air outlet direction of the air blower; in the first state, the air outlet end of the air blower is in communication with the air inlet of the hearth through the valve, and the valve 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 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 in communication with the air inlet end of the second channel through the valve; the operation method comprises the following steps: S1, system preheating, comprising the following steps: S11, the crucible is arranged in the hearth before the system is started; S12, the valve is switched to the first state; S13, the air blower is started, and the burner is turned on to perform combustion; the hot air in the hearth flows through the first channel through the air outlet to heat the heat accumulation medium in the first channel; S2, when the temperature of the heat accumulation medium reaches a set value, the valve is switched to the second state; S3, the material to be smelted is placed in the crucible in the hearth; S4, when the temperature of the material in the crucible reaches a set value, the crucible is taken out, and the smelted material is poured out.

2. The method of operating a regenerative combustion system according to claim 1, wherein, The system further comprises a pipeline assembly; the pipeline assembly comprises a first pipeline and a second pipeline; the first end of the first pipeline is in communication with the air outlet end of the second channel, the second end of the first pipeline is in communication with the air inlet of the hearth; the first pipeline is further connected to the air outlet end of the air blower through the valve; the first end of the second pipeline is in communication with the air inlet end of the second channel; the second end of the second pipeline is connected to the air outlet end of the air blower through the valve.

3. The method of operating a regenerative combustion system according to claim 2, wherein, The valve comprises a three-way valve, which includes an air inlet valve port, two air outlet valve ports and a valve plate; the air inlet valve port is communicated with the air outlet end of the air blower; one of the two air outlet valve ports 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 air outlet valve ports to control the opening / closing of the corresponding air outlet valve port.

4. The method of operating a regenerative combustion system according to claim 2, wherein, The valve comprises two valves, and the second ends of the first pipeline and the second pipeline are communicated through a communication pipe, and the two valves are arranged on the communication pipe at intervals; the communication pipe is communicated with the air outlet end of the air blower at the position between the two valves.

5. The method of operating 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.

6. The method of operating a regenerative combustion system of claim 1, wherein, The system further comprises a chimney, which is communicated with the air outlet end of the first channel.

7. The method of operating a regenerative combustion system according to claim 1, wherein, The air inlet end of the burner is provided with a natural gas flow meter for adjusting the amount of natural gas; and / or the air outlet end of the air blower is provided with an air flow meter for adjusting the air volume output by the air blower.

8. The method of operating a regenerative combustion system of claim 1, wherein, Among the four positions, at least one of which is provided with a temperature detection device for detecting temperature, is the inside of the furnace, the exhaust port of the furnace, the air inlet end of the first channel, the air outlet end of the second channel and the air inlet port of the furnace. The heat storage medium is at least one of alumina balls, silicon carbide balls and zirconia balls. The system further comprises a chimney, which is communicated with the air outlet end of the first channel. The air inlet end of the burner is provided with a natural gas flow meter for adjusting the amount of natural gas; and / or the air outlet end of the air blower is provided with an air flow meter for adjusting the air volume output by the air blower. Among the four positions, at least one of which is provided with a temperature detection device for detecting temperature, is the inside of the furnace, the exhaust port of the furnace, the air inlet end of the first channel, the air outlet end of the second channel and the air inlet port of the furnace.

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