Process for recovering waste heat of sintering ore direct heating boiler

Abstract

The invention belongs to the technical field of sintering waste heat recovery, and discloses a process for recovering waste heat of a sintering ore direct heating boiler. Comprising the steps that sintered high-temperature sintered ore is directly added into a waste heat recovery boiler, and heat energy of the high-temperature sintered ore is used for heating a cooling medium in the waste heat recovery boiler so as to recover heat. According to the technology for recycling waste heat of the sintering ore direct heating boiler, the sintering ore energy recycling efficiency can be effectively improved, the technological process is simplified, and the equipment investment and the operation and maintenance cost are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of sintering waste heat recovery, and in particular to a process for recovering waste heat by directly heating a sintered ore boiler. Background Art

[0002] Among the various processes in steel production, the energy consumption of the sintering process accounts for about 10% of the total process, second only to the blast furnace. The temperature range of the sintered ore discharged from the tail of the sintering machine is generally 500-750℃, or even 800℃. Its sensible heat accounts for about 35%-45% of the total energy consumption of the sintering process. The sintered ore is cooled on the ring cooler, and the heat contained in the sintered ore is converted into sensible heat of the exhaust gas. The exhaust gas temperature varies between 120 and 450℃ depending on the location of the ring cooler.

[0003] At present, the traditional sintering waste heat utilization process is as follows: after the high-temperature sintered ore is unloaded from the sintering machine, it enters the ring cooler for cooling; the ring cooler cools the sintered ore and produces high-temperature flue gas (120-450℃); the high-temperature flue gas is introduced into the waste heat boiler to heat the cooling medium in the waste heat boiler to generate steam; then the steam enters the steam turbine generator set for power generation or heating; the cooled sintered ore is sent to the next process. Although the traditional sintering waste heat utilization process is mature in technology and widely used, and can recover part of the sensible heat of the sintered ore, it still has the following disadvantages: 1) Low energy recovery efficiency: the heat energy of the sintered ore is transferred twice through the flue gas, resulting in heat loss; 2) Complex process flow: involving multiple equipment such as ring coolers, waste heat boilers, and steam turbine generator sets, the equipment investment is high; 3) Large footprint: equipment such as ring coolers and waste heat boilers require a large installation space; 4) High operation and maintenance costs: There are many equipment and a large maintenance workload.

[0004] Therefore, there is an urgent need for a waste heat recovery process that can improve the energy recovery efficiency of sintered ore, simplify the process flow and reduce equipment investment. Summary of the invention

[0005] In order to improve the energy recovery efficiency of sintered ore, simplify the process flow and reduce equipment investment and operation and maintenance costs, the present invention proposes a process for recovering waste heat by directly heating a sintered ore boiler.

[0006] The process of recovering waste heat by directly heating a boiler with sintered ore according to the present invention comprises: directly adding the high-temperature sintered ore that has been sintered into a waste heat recovery boiler, and using the heat energy of the high-temperature sintered ore to heat the cooling medium in the waste heat recovery boiler to recover heat.

[0007] Furthermore, the heat energy of the high-temperature sintered ore is directly transferred to the cooling medium in the waste heat recovery boiler through the heating surface of the waste heat recovery boiler.

[0008] Furthermore, the high-temperature sintered ore is directly transported to the waste heat recovery boiler through a mechanical insulation device.

[0009] Furthermore, the high temperature sintered ore is crushed before entering the mechanical heat preservation device.

[0010] Furthermore, the waste heat recovery boiler adopts a vertical furnace structure.

[0011] Furthermore, the mechanical insulation device goes up along the loading position at the bottom of the inclined bridge to the top feed port of the waste heat recovery boiler. The high-temperature sintered ore is crushed by a crusher before entering the mechanical insulation device. The sintered high-temperature sintered ore falls onto the first belt conveyor. The crusher is located between the drop port of the first belt conveyor and the loading position of the mechanical insulation device.

[0012] Furthermore, the high-temperature steam generated by the waste heat recovery boiler is used to generate electricity or heat for users.

[0013] Furthermore, the high-temperature sintered ore is discharged from the waste heat recovery boiler after the heat is recovered by the waste heat recovery boiler, and is transported to the next process.

[0014] Furthermore, the high-temperature sintered ore discharged after the heat is recovered by the waste heat recovery boiler is transported to the next process through the second belt conveyor.

[0015] Furthermore, the heating surface of the waste heat recovery boiler is made of high-chromium cast iron or wear-resistant steel material; the inner lining of the waste heat recovery boiler is made of corundum refractory material and wear-resistant coating.

[0016] Compared with the prior art, the process of recovering waste heat by directly heating a boiler with sintered ore in the present invention achieves the following beneficial effects by optimizing the process flow and material selection:

[0017] 1) Improved energy recovery efficiency: The sensible heat of sintered ore is directly recovered through solid-solid heat exchange, which avoids the waste caused by secondary heat transfer and realizes the efficient recovery of sensible heat of sintered ore;

[0018] 2) Simplified process flow: eliminating equipment such as annular coolers, reducing equipment investment and floor space;

[0019] 3) Reduced operation and maintenance costs: less equipment, simple process flow, simple maintenance, which reduces the operation and maintenance costs in the production process and improves economic benefits;

[0020] 4) Improved equipment durability: Use of highly wear-resistant and high-temperature resistant materials prolongs the service life of the waste heat recovery boiler;

[0021] 5) Comprehensive utilization of energy is achieved: high-temperature steam can be used for power generation or heating, thus improving energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1It is a schematic diagram of the working process of a process for recovering waste heat by directly heating a boiler with sintered ore according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings.

[0024] Figure 1 The working process of the process of recovering waste heat by directly heating a sintered ore boiler according to an embodiment of the present invention is shown. Figure 1 As shown, the process of recovering waste heat by directly heating a boiler with sintered ore of the present invention may include: directly adding the high-temperature sintered ore 1 that has been sintered into a waste heat recovery boiler 4, and using the heat energy of the high-temperature sintered ore to heat the cooling medium in the waste heat recovery boiler 4 to recover heat.

[0025] The process of directly heating a sintered ore boiler to recover waste heat of the present invention directly adds high-temperature sintered ore 1 to a waste heat recovery boiler 4, and uses the thermal energy of the sintered ore to heat the cooling medium in the waste heat recovery boiler 4, thereby avoiding energy loss caused by secondary heat transfer through flue gas in traditional processes and effectively improving energy recovery efficiency. The process of directly heating a sintered ore boiler to recover waste heat of the present invention omits the process of cooling the sintered ore with a ring cooler, simplifies the process flow, reduces equipment investment and operation and maintenance costs, and can bring significant economic benefits to the sintering plant.

[0026] According to the present invention, the heat energy of the high-temperature sintered ore 1 is directly transferred to the cooling medium in the waste heat recovery boiler 4 through the heating surface of the waste heat recovery boiler 4. Such a setting enables the process of recovering waste heat by directly heating the sintered ore boiler of the present invention to adopt a solid-solid direct heat exchange method, which reduces the energy loss in the heat transfer process, greatly improves the heat exchange efficiency, and makes the heat energy recovery more sufficient; at the same time, it also reduces the thermal stress in the operation of the waste heat recovery boiler 4 and prolongs the service life of the equipment.

[0027] In such Figure 1 In the preferred embodiment shown, the high-temperature sintered ore 1 can be directly transported to the waste heat recovery boiler 4 through the mechanical heat preservation device 3. The mechanical heat preservation device 4 reduces the heat loss of the high-temperature sintered ore 1 during transportation, improves the utilization rate of thermal energy; and also helps to simplify the transportation process, thereby reducing the complexity and floor space of the equipment, and improving the stability and continuity of the transportation of the high-temperature sintered ore 1.

[0028] In such Figure 1In the preferred embodiment shown, the high-temperature sintered ore 1 can be crushed before entering the mechanical heat preservation device 3. The crushed sintered ore has a more uniform particle size, which is beneficial to improving the heat exchange efficiency; at the same time, it also reduces the risk of accumulation and blockage of the sintered ore in the waste heat recovery boiler 4, and improves the stability of the operation of the waste heat recovery boiler 4; in addition, this arrangement also facilitates the transportation and processing of the sintered ore in the mechanical heat preservation device 3 and the waste heat recovery boiler 4.

[0029] Furthermore, if Figure 1 As shown, the waste heat recovery boiler 4 can adopt a vertical furnace structure. The vertical furnace structure is conducive to the full contact between the sintered ore and the cooling medium, and improves the heat exchange efficiency; at the same time, the vertical furnace structure is compact, which reduces the footprint of the boiler; in addition, it is convenient for the feeding and discharging of the sintered ore, and improves the continuity of the process flow.

[0030] In such Figure 1 In the preferred embodiment shown, the mechanical heat preservation device 3 goes up along the loading position 31 at the bottom of the inclined bridge 9 to the top feed port of the waste heat recovery boiler 4, and the high-temperature sintered ore 1 is crushed by the crusher 2 before entering the mechanical heat preservation device 3. The sintered high-temperature sintered ore 1 falls onto the first belt conveyor 7, and the crusher 2 is located between the drop port of the first belt conveyor 7 and the loading position of the mechanical heat preservation device 3. In this embodiment, the combination of the inclined bridge 9 and the first belt conveyor 7 realizes the continuous transportation of the sintered ore and improves the production efficiency; the setting of the crusher 2 makes the sintered ore particle size more uniform, which is conducive to improving the heat exchange efficiency; the mechanical heat preservation device 3 reduces heat loss and improves the utilization rate of thermal energy.

[0031] Furthermore, if Figure 1 As shown, the high-temperature steam generated by the waste heat recovery boiler 4 is used to generate electricity or provide heat for the user 5, so as to achieve efficient utilization of the waste heat of sintered ore and reduce the energy consumption of the sintering plant; the high-temperature steam can be used for power generation or heat supply, which brings significant economic benefits to the sintering plant while reducing dependence on external energy and improving energy self-sufficiency.

[0032] According to the present invention, the high-temperature sintered ore is discharged from the waste heat recovery boiler 4 after the waste heat recovery boiler recovers the heat, and the low-temperature sintered ore 6 is transported to the next process. This arrangement realizes the full recovery of the waste heat of the sintered ore and improves the energy utilization efficiency; the cooled sintered ore can be directly used in the next process, simplifying the process flow.

[0033] Furthermore, if Figure 1 As shown, the low-temperature sintered ore 6 can be transported to the next process through the second belt conveyor 8. The second belt conveyor 8 realizes the continuous transportation of the cooled sintered ore, improves production efficiency, simplifies the material transportation process, reduces equipment complexity and floor space, improves the automation of the process, and reduces manual operations.

[0034] According to the present invention, the heating surface of the waste heat recovery boiler 4 can be preferably made of high-chromium cast iron or wear-resistant steel; the lining of the waste heat recovery boiler 4 can be preferably made of corundum refractory material and wear-resistant coating (such as silicon carbide wear-resistant castable). High-chromium cast iron and wear-resistant steel materials have excellent wear resistance and high temperature resistance, which extend the service life of the heating surface; corundum refractory materials and wear-resistant coatings improve the wear resistance and heat insulation performance of the lining, and reduce the heat loss of the boiler; the selection of overall materials improves the durability and operation stability of the boiler and reduces maintenance costs.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A process for recovering waste heat from a sintered ore direct heating boiler, characterized in that: include: The high-temperature sintered ore that has been sintered is directly added to the waste heat recovery boiler, and the heat energy of the high-temperature sintered ore is used to heat the cooling medium in the waste heat recovery boiler to recover heat.

2. The process for recovering waste heat from a sintered ore direct heating boiler according to claim 1, characterized in that: The heat energy of the high-temperature sintered ore is directly transferred to the cooling medium in the waste heat recovery boiler through the heating surface of the waste heat recovery boiler.

3. The process for recovering waste heat from a sintered ore direct heating boiler according to claim 1 or 2, characterized in that: The high-temperature sintered ore is directly transported to the waste heat recovery boiler through a mechanical insulation device.

4. The process for recovering waste heat from a sintered ore direct heating boiler according to claim 3, characterized in that: The high-temperature sintered ore is crushed before entering the mechanical heat preservation device.

5. The process for recovering waste heat from a sintered ore direct heating boiler according to claim 4, characterized in that: The waste heat recovery boiler adopts a vertical furnace structure.

6. The process for recovering waste heat from a sintered ore direct heating boiler according to claim 5, characterized in that: The mechanical insulation device goes up along the loading position at the bottom of the inclined bridge to the top feed port of the waste heat recovery boiler. The high-temperature sintered ore is crushed by a crusher before entering the mechanical insulation device. The high-temperature sintered ore after sintering falls onto the first belt conveyor. The crusher is located between the drop port of the first belt conveyor and the loading position of the mechanical insulation device.

7. The process for recovering waste heat from a sintered ore direct heating boiler according to claim 1 or 2, characterized in that: The high-temperature steam generated by the waste heat recovery boiler is used to generate electricity or provide heat for users.

8. The process for recovering waste heat from a sintered ore direct heating boiler according to claim 1 or 2, characterized in that: The high-temperature sintered ore is discharged from the waste heat recovery boiler after the heat is recovered by the waste heat recovery boiler, and is transported to the next process.

9. The process for recovering waste heat from a sintered ore direct heating boiler according to claim 8, characterized in that: The high-temperature sintered ore discharged after the heat is recovered by the waste heat recovery boiler is transported to the next process through the second belt conveyor.

10. The process for recovering waste heat from a sintered ore direct heating boiler according to claim 2, characterized in that: The heating surface of the waste heat recovery boiler is made of high-chromium cast iron or wear-resistant steel; the inner lining of the waste heat recovery boiler is made of corundum refractory material and wear-resistant coating.

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