A double-box regenerative heat exchanger

Abstract

The application provides a double-box heat accumulating heat exchanger and relates to the field of industrial furnaces. The double-box heat accumulating heat exchanger comprises a heat accumulating heat exchange box, a flexible interlocking double four-way valve, a pipeline, a flow regulating valve, a flow regulating valve, a combustion air variable frequency blower and an exhaust gas variable frequency induced draft fan. The heat accumulating heat exchange box comprises a heat accumulating heat exchange box A and a heat accumulating heat exchange box B, and the heat accumulating heat exchange box A and the heat accumulating heat exchange box B are of the same structure. The double-box heat accumulating heat exchanger has the advantages of high thermal efficiency, high heating quality of the heated workpiece, high cost performance, small occupied area and the like.

Description

Technical Field

[0001] This invention relates to the field of industrial furnace technology, specifically to a dual-box regenerative heat exchanger. Background Technology

[0002] Technological advancements in industrial furnaces play a vital role in industrial development. Heat exchangers, which utilize the waste heat from flue gas emitted by the furnace to heat combustion air and gaseous fuels, are crucial for energy conservation and emission reduction in industrial furnaces. Traditional metal heat exchangers suffer from low temperature resistance, short service life, high exhaust gas temperatures, and low heat exchange efficiency (approximately 15%–25%). Conventional gas burners, which either do not preheat the combustion air or preheat it via a metal heat exchanger, also have low thermal efficiency. However, they offer the advantage of continuous heating, a longer convection path for the high-temperature flue gas to heat the workpiece within the furnace, and the formation of continuous heating zones from high to medium to low temperatures, resulting in more efficient workpiece heating and higher heating quality.

[0003] In burner-type regenerative heating furnaces, burners are generally arranged in pairs. The workpiece is heated well when it is between two sets of burners. In areas of the furnace without burners, the heat flux density is low and the heating is poor. This is especially true for long through-type heating furnaces. In order to ensure the heating effect, burners must be arranged along the entire length of the furnace, which forces an increase in the number of burners by one to several times. In addition, there are many heating temperature zones in the furnace, making control complex. The temperature gradient between the temperature zones is large, which greatly affects the heating quality of the workpiece. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a dual-box regenerative heat exchanger, which solves the problems of low heat flux density, poor heating, and low thermal efficiency in existing burner regenerative heating furnaces.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A dual-box regenerative heat exchanger comprises a regenerative heat exchange box, a flexible interlocking double four-way valve, pipelines, a flow regulating valve, a combustion air variable frequency blower, and a smoke exhaust variable frequency induced draft fan. The regenerative heat exchange box includes regenerative heat exchange box A and regenerative heat exchange box B, and regenerative heat exchange box A and regenerative heat exchange box B have the same structure. Regenerative heat exchange box A includes a steel structure, an insulation layer, refractory materials, a low-temperature chamber A, a heat storage body support grate, a heat storage body, a high-temperature chamber A, a heat storage chamber cover, a low-temperature interface A for flue gas and combustion air, and a high-temperature interface A for flue gas and combustion air. Regenerative heat exchange box B includes a steel structure, an insulation layer, refractory materials, a low-temperature chamber B, a heat storage body support grate, a heat storage body, a high-temperature chamber B, and a heat storage chamber cover.

[0009] The flexible interlocking double four-way valve consists of a two-position four-way flue gas and air-cooled reversing valve and a two-position four-way flue gas and air-heated reversing valve.

[0010] The pipeline consists of a flue gas and combustion air cryogenic pipeline A, a flue gas and combustion air cryogenic pipeline B, and a cryogenic exhaust pipeline.

[0011] Preferably, the heat storage heat exchange box A includes a steel structure, with an insulation layer provided on the inner sidewall and bottom of the steel structure. The inner sidewall of the insulation layer is provided with refractory material, and a heat storage chamber A is formed inside the insulation layer. A low-temperature cavity of heat storage chamber A is fixedly connected to the bottom center of the heat storage chamber A. A heat storage body support grate is fixedly connected to the top of the low-temperature cavity of heat storage chamber A. A heat storage body is fixedly connected to the top of the heat storage body support grate. A high-temperature cavity of heat storage chamber A is fixedly connected to the top of the heat storage body. A heat storage chamber cover plate is provided on the top of the high-temperature cavity of heat storage chamber A.

[0012] Preferably, the heat storage heat exchange box B includes a steel structure, with an insulation layer on the inner wall and bottom of the steel structure. The inner wall of the insulation layer is lined with refractory material, and a heat storage chamber B is formed inside the insulation layer. A low-temperature chamber B is fixedly connected to the bottom center of the heat storage chamber B. A heat storage body support grate is fixedly connected to the top of the low-temperature chamber B. A heat storage body is fixedly connected to the top of the heat storage body support grate. A high-temperature chamber B is located on top of the heat storage body. A heat storage chamber cover plate is provided on the top of the high-temperature chamber B.

[0013] Preferably, the heat storage chamber A of the heat storage box A is fixedly connected to a high-temperature interface A for flue gas and combustion air. A two-position four-way flue gas and air heat diversion valve is fixedly connected to the end of the high-temperature chamber A away from the heat storage chamber A. The heat storage chamber B of the heat storage box B is fixedly connected to a high-temperature interface B for flue gas and combustion air. The high-temperature interface B for flue gas and combustion air is fixedly connected to the two-position four-way flue gas and air heat diversion valve. A high-temperature flue gas inlet is fixedly connected to the top of the two-position four-way flue gas and air heat diversion valve, and a high-temperature air outlet is fixedly connected to the bottom of the two-position four-way flue gas and air heat diversion valve.

[0014] Preferably, the low-temperature chamber sidewall of the heat storage chamber A of the heat storage box A is fixedly connected to a low-temperature flue gas and combustion air interface A, and a two-position four-way flue gas and air cooling reversing valve is fixedly connected to the end face of the low-temperature flue gas and combustion air interface A. Similarly, the low-temperature flue gas and combustion air interface B of the heat storage chamber B of the heat storage box B is fixedly connected to a low-temperature flue gas and combustion air interface B, and the low-temperature flue gas and combustion air interface B is fixedly connected to the two-position four-way flue gas and air cooling reversing valve. A flow regulating valve is connected to the bottom of the valve via a connecting pipe. The end of the flow regulating valve away from the two-position four-way flue gas and air-cooled reversing valve is connected to a combustion air variable frequency blower via a connecting pipe. The top of the two-position four-way flue gas and air-cooled reversing valve is connected to a flow regulating valve via a connecting pipe. The end of the flow regulating valve away from the two-position four-way flue gas and air-cooled reversing valve is connected to a smoke exhaust variable frequency induced draft fan via a connecting pipe. A low-temperature smoke exhaust duct is fixedly connected to the end of the smoke exhaust variable frequency induced draft fan away from the flow regulating valve.

[0015] Working principle: Schematic diagram of the first working state of the dual-box regenerative heat exchanger of the present invention Figure 1Combustion air is blown into the pipeline by the variable frequency blower 13, and the flow rate is regulated by the flow regulating valve 14. Then it enters the two-position four-way flue gas and air cooling reversing valve 15 to achieve reversal. It enters the low-temperature chamber 4 of the heat storage chamber A and the heat storage support grate 5 through the low-temperature flue gas and combustion air pipeline A 12. Heat exchange between the combustion air and the heat storage body 6 is achieved through the high-temperature heat storage body 6. At this time, the combustion air is preheated and the heat storage body 6 is cooled. The preheated combustion air flows through the high-temperature chamber 9 of the heat storage chamber A and is reversed by the two-position four-way flue gas and air cooling reversing valve 21 to enter the burner through the high-temperature air outlet 25 to participate in combustion. At the same time, the high-temperature flue gas below 1100°C discharged from the heating furnace is reversed by the two-position four-way flue gas and air cooling reversing valve 21 and enters the burner through the high-temperature flue gas and combustion air interface B. 22 enters the high-temperature chamber 23 of the heat storage chamber B, where heat exchange between the high-temperature flue gas and the low-temperature heat storage body is completed. At this time, the high-temperature flue gas is cooled to a low-temperature flue gas below 80°C, and the heat storage body is heated to a high-temperature state. The cooled low-temperature flue gas enters the low-temperature flue gas and combustion air pipe B 18 through the low-temperature chamber 26 of the heat storage chamber B and the low-temperature flue gas and combustion air interface B 27. Then, it is reversed by the two-position four-way flue gas and air cooling reversing valve 15, and the flow regulating valve 16 regulates the flow. After being drawn into the pipe by the flue gas exhaust variable frequency induced draft fan 17, it is discharged through the low-temperature exhaust pipe 19. Similarly, the schematic diagram of the second working state structure of the dual-box heat storage heat exchanger of the present invention is shown. Figure 2 Working principle and structural diagram of the first working state of the dual-box regenerative heat exchanger Figure 1 The two operating states, A and B, of the dual-box regenerative heat exchanger alternately. Combustion air, after being efficiently preheated by the dual-box regenerative heat exchanger, is continuously supplied to the burner for combustion, enabling continuous heating of the workpiece. Simultaneously, high-temperature flue gas below 1100℃ is cooled to below 80℃ by passing through the dual-box regenerative heat exchanger. This invention, employing the dual-box regenerative heat exchanger technology, combines the heating advantages of both conventional and regenerative burners while eliminating their disadvantages. It boasts advantages such as high thermal efficiency, high-quality heating of the workpiece, high cost-effectiveness, and small footprint.

[0016] (III) Beneficial Effects

[0017] This invention provides a dual-box regenerative heat exchanger. It has the following beneficial effects:

[0018] 1. This invention proposes a dual-box regenerative heat exchanger, which achieves the ultimate recovery of waste heat from exhaust gas from forging furnaces or heat treatment furnaces when the flue gas inlet temperature is 1100℃ and the flue gas outlet temperature is within 80℃, resulting in outstanding energy saving and emission reduction effects.

[0019] 2. This invention proposes a double-box regenerative heat exchanger, in which the combustion air is efficiently preheated by the double-box regenerative heat exchanger and continuously supplied to the burner to participate in combustion, which can realize continuous heating of the workpiece by the burner. It is especially suitable for through heating furnaces with a furnace length and furnace width greater than 5. A continuous heating zone of high temperature, medium temperature and low temperature can be formed in the length direction of the furnace, the workpiece is heated reasonably and the heating quality of the heated workpiece is high.

[0020] 3. This invention proposes a dual-box regenerative heat exchanger. Due to the use of non-metallic refractory materials for the heat exchange medium and the inner wall of the box, the heat exchanger has good heat resistance, long service life, and high cost performance.

[0021] 4. This invention proposes a dual-box regenerative heat exchanger, which has a dual four-way valve consisting of a cold four-way valve and a hot four-way valve. The cold four-way valve is installed on the upper layer and the hot four-way valve is installed on the lower layer. The dual four-way valves adopt flexible interlocking to ensure flexible synchronization when the dual four-way valves are working, and the valve plate and valve seat of the four-way valve are reliably sealed. Attached Figure Description

[0022] Figure 1 This invention provides a schematic diagram of the first working state structure of a dual-box regenerative heat exchanger.

[0023] Figure 2 This invention presents a schematic diagram of the second working state structure of a dual-box regenerative heat exchanger.

[0024] The components include: 1. Low-temperature interface A for flue gas and combustion air; 2. Steel structure; 3. Heat storage chamber A; 4. Low-temperature cavity of heat storage chamber A; 5. Heat storage body support grate; 6. Heat storage body; 7. Insulation layer; 8. Refractory material; 9. High-temperature cavity of heat storage chamber A; 10. Heat storage chamber cover plate; 11. High-temperature interface A for flue gas and combustion air; 12. Low-temperature duct A for flue gas and combustion air; 13. Variable frequency blower for combustion air; 14. Flow regulating valve; 15. Two-position four-way flue gas... 16. Air-cooled reversing valve; 17. Flow regulating valve; 18. Smoke exhaust variable frequency induced draft fan; 19. Low-temperature flue gas and combustion air duct B; 20. Low-temperature smoke exhaust duct; 21. High-temperature flue gas inlet; 22. Two-position four-way flue gas and air hot reversing valve; 23. High-temperature interface B for flue gas and combustion air; 24. High-temperature chamber B of heat storage chamber; 25. High-temperature air outlet; 26. Low-temperature chamber B of heat storage chamber; 27. Low-temperature interface B for flue gas and combustion air. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example:

[0027] like Figure 1 As shown in Figure 2, this embodiment of the invention provides a dual-box regenerative heat exchanger, comprising a regenerative heat exchange box, a flexible interlocking double four-way valve, pipelines, a flow regulating valve 14, a flow regulating valve 16, a combustion air variable frequency blower 13, and a smoke exhaust variable frequency induced draft fan 17. The regenerative heat exchange box includes regenerative heat exchange box A and regenerative heat exchange box B, and regenerative heat exchange box A and regenerative heat exchange box B have the same structure. Regenerative heat exchange box A includes a steel structure 2. The heat storage heat exchange box B includes a steel structure 2, an insulation layer 7, a refractory material 8, a heat storage chamber A low-temperature cavity 4, a heat storage body support grate 5, a heat storage body 6, a heat storage chamber A high-temperature cavity 9, a heat storage chamber cover plate 10, a flue gas and combustion air low-temperature interface A1 and a flue gas and combustion air high-temperature interface A11;

[0028] The flexible interlocking double four-way valve consists of a two-position four-way flue gas and air-cooled reversing valve 15 and a two-position four-way flue gas and air-heated reversing valve 21.

[0029] The pipeline consists of a flue gas and combustion air cryogenic pipeline A12, a flue gas and combustion air cryogenic pipeline B18, and a cryogenic exhaust pipeline 19.

[0030] The heat storage heat exchange box A includes a steel structure 2. The inner wall and bottom of the steel structure 2 are provided with an insulation layer 7. The inner wall of the insulation layer 7 is provided with refractory material 8. The insulation layer 7 forms a heat storage chamber A3. The low temperature chamber 4 of the heat storage chamber A is fixedly connected to the bottom center of the heat storage chamber A3. The top of the low temperature chamber 4 of the heat storage chamber A is fixedly connected with a heat storage body support grate 5. The top of the heat storage body support grate 5 is fixedly connected with a heat storage body 6. The top of the heat storage body 6 is fixedly connected with a high temperature chamber 9 of the heat storage chamber A. The top of the high temperature chamber 9 of the heat storage chamber A is provided with a heat storage chamber cover plate 10.

[0031] The heat storage heat exchange box B includes a steel structure 2. The inner wall and bottom of the steel structure 2 are provided with an insulation layer 7. The inner wall of the insulation layer 7 is provided with refractory material 8. The insulation layer 7 forms a heat storage chamber B24. The bottom center of the heat storage chamber B24 is fixedly connected to a low temperature chamber 26. The top of the low temperature chamber 26 is fixedly connected to a heat storage body support grate 5. The top of the heat storage body support grate 5 is fixedly connected to a heat storage body 6. The top of the heat storage body 6 is a high temperature chamber 23 of the heat storage chamber B. The top of the high temperature chamber 23 is provided with a heat storage chamber cover plate 10.

[0032] A high-temperature flue gas and combustion air interface A11 is fixedly connected to the side wall of the high-temperature chamber 9 of the heat storage chamber A of the heat storage box A. A two-position four-way flue gas and air heat reversing valve 21 is fixedly connected to the end of the high-temperature chamber 9 of the heat storage box A. A high-temperature flue gas and combustion air interface B22 is fixedly connected to the side wall of the high-temperature chamber 23 of the heat storage chamber B of the heat storage box B. The high-temperature flue gas and combustion air interface B22 is fixedly connected to the two-position four-way flue gas and air heat reversing valve 21. A high-temperature flue gas inlet 20 is fixedly connected to the top of the two-position four-way flue gas and air heat reversing valve 21. A high-temperature air outlet 25 is fixedly connected to the bottom of the two-position four-way flue gas and air heat reversing valve 21.

[0033] A low-temperature chamber 4 of the heat storage chamber A of the heat storage box A is fixedly connected to a low-temperature interface A1 for flue gas and combustion air. A two-position four-way flue gas and air cooling reversing valve 15 is fixedly connected to the end face of the low-temperature interface A1. A low-temperature interface B27 for flue gas and combustion air is fixedly connected to the side wall of the low-temperature chamber 26 of the heat storage chamber B of the heat storage box B. The low-temperature interface B27 is fixedly connected to the two-position four-way flue gas and air cooling reversing valve 15. The bottom of the two-position four-way flue gas and air cooling reversing valve 15 is connected via a... A flow regulating valve 14 is connected to the pipe. The end of the flow regulating valve 14 away from the two-position four-way flue gas and air-cooled reversing valve 15 is connected to a combustion air variable frequency blower 13 via a connecting pipe. The top of the two-position four-way flue gas and air-cooled reversing valve 15 is connected to a flow regulating valve 16 via a connecting pipe. The end of the flow regulating valve 16 away from the two-position four-way flue gas and air-cooled reversing valve 15 is connected to a smoke exhaust variable frequency induced draft fan 17 via a connecting pipe. The end of the smoke exhaust variable frequency induced draft fan 17 away from the flow regulating valve 16 is fixedly connected to a low-temperature smoke exhaust pipe 19.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dual-box regenerative heat exchanger, comprising a regenerative heat exchange box, a flexible interlocking double four-way valve, pipelines, a first flow regulating valve (14), a second flow regulating valve (16), a combustion air variable frequency blower (13), and a smoke exhaust variable frequency induced draft fan (17), characterized in that: The heat storage heat exchange box includes heat storage heat exchange box A and heat storage heat exchange box B, and heat storage heat exchange box A and heat storage heat exchange box B have the same structure. The heat storage heat exchange box A includes a steel structure (2), insulation layer (7), refractory material (8), heat storage chamber A low temperature cavity (4), heat storage body support grate (5), heat storage body (6), heat storage chamber A high temperature cavity (9), heat storage chamber cover plate (10), flue gas and combustion air low temperature interface A (1) and flue gas and combustion air high temperature interface A (11). The heat storage heat exchange box B includes a steel structure (2), insulation layer (7), refractory material (8), heat storage chamber B low temperature cavity (26), heat storage body support grate (5), heat storage body (6), heat storage chamber B high temperature cavity (23) and heat storage chamber cover plate (10). The flexible interlocking double four-way valve consists of a two-position four-way flue gas and air-cooled reversing valve (15) and a two-position four-way flue gas and air-heated reversing valve (21); The pipeline consists of a flue gas and combustion air cryogenic pipeline A (12), a flue gas and combustion air cryogenic pipeline B (18), and a cryogenic exhaust pipeline (19); The heat storage heat exchange box A includes a steel structure (2), the inner wall and bottom of the steel structure (2) are provided with a heat insulation layer (7), the inner wall of the heat insulation layer (7) is provided with refractory material (8), the heat insulation layer (7) forms a heat storage chamber A (3), the bottom center of the heat storage chamber A (3) is fixedly connected to a low temperature chamber A (4), the top of the low temperature chamber A (4) is fixedly connected to a heat storage body support grate (5), the top of the heat storage body support grate (5) is fixedly connected to a heat storage body (6), the top of the heat storage body (6) is fixedly connected to a high temperature chamber A (9), and the top of the high temperature chamber A (9) is provided with a heat storage chamber cover plate (10). The heat storage heat exchange box B includes a steel structure (2), the inner wall and bottom of the steel structure (2) are provided with a heat insulation layer (7), the inner wall of the heat insulation layer (7) is provided with refractory material (8), the heat insulation layer (7) forms a heat storage chamber B (24), the bottom center of the heat storage chamber B (24) is fixedly connected to a low temperature chamber (26), the top of the low temperature chamber B (26) is fixedly connected to a heat storage body support grate (5), the top of the heat storage body support grate (5) is fixedly connected to a heat storage body (6), the top of the heat storage body (6) is a high temperature chamber B (23), and the top of the high temperature chamber B (23) is provided with a heat storage chamber cover plate (10). The heat storage chamber A of the heat storage box A has a high-temperature interface A (11) for flue gas and combustion air fixedly connected to the side wall of the high-temperature cavity (9) of the heat storage chamber A. The end of the high-temperature cavity (9) of the heat storage chamber A (11) away from the high-temperature cavity (9) of the heat storage chamber A (21) is fixedly connected to a two-position four-way flue gas and air heat reversing valve (21). The heat storage chamber B of the heat storage box B has a high-temperature interface B (22) for flue gas and combustion air fixedly connected to the side wall of the high-temperature cavity (23) of the heat storage box B. The high-temperature interface B (22) for flue gas and combustion air is fixedly connected to the two-position four-way flue gas and air heat reversing valve (21). The top of the two-position four-way flue gas and air heat reversing valve (21) is fixedly connected to a high-temperature flue gas inlet (20). The bottom of the two-position four-way flue gas and air heat reversing valve (21) is fixedly connected to a high-temperature air outlet (25). The heat storage chamber A of the heat storage box A has a low-temperature cavity (4) with a flue gas and combustion air low-temperature interface A (1) fixedly connected to its side wall. A two-position four-way flue gas and air cooling reversing valve (15) is fixedly connected to the end face of the flue gas and combustion air low-temperature interface A (1). The heat storage chamber B of the heat storage box B has a low-temperature cavity (26) with a flue gas and combustion air low-temperature interface B (27) fixedly connected to its side wall. The flue gas and combustion air low-temperature interface B (27) is fixedly connected to the two-position four-way flue gas and air cooling reversing valve (15). The bottom of the two-position four-way flue gas and air cooling reversing valve (15) is connected to a flow meter via a connecting pipe. A flow regulating valve (14) is connected to a combustion air variable frequency blower (13) via a connecting pipe at the end of the two-position four-way flue gas and air-cooled reversing valve (15). A flow regulating valve (16) is connected to the top of the two-position four-way flue gas and air-cooled reversing valve (15) via a connecting pipe. A smoke exhaust variable frequency induced draft fan (17) is connected to the end of the two-position four-way flue gas and air-cooled reversing valve (15) via a connecting pipe. A low-temperature smoke exhaust pipe (19) is fixedly connected to the end of the smoke exhaust variable frequency induced draft fan (17) away from the end of the flow regulating valve (16).

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