System integrating thermal power generation and cement production

Abstract

The utility model provides a thermal power generation and cement production integrated system which comprises a circulating fluidized bed boiler, and the boiler comprises a circulating gas inlet arranged to the middle part; the air pipeline and the flue gas pipeline pass through the heat exchanger, so that heat exchange between air and flue gas is realized; one end of the circulating gas pipeline is communicated to the flue gas pipeline, and the other end is communicated to the circulating gas inlet for returning the flue gas to the boiler again; the steam generating device is communicated to a hearth of the boiler and is used for generating steam; the steam turbine is connected to the steam generating device, and the other end of the steam turbine is connected to the generator; the slag cooler is communicated to the slag discharge port and is used for cooling the calcined product; the cement production line device is used for producing cement clinker; the slag cooler and the cement production line device are both connected to the cement mill, so that the cooled calcined product is mixed and ground with cement clinker to produce cement. According to the system provided by the utility model, power generation and cement production can be realized at the same time, and the generated flue gas can be recycled.

Description

Technical Field

[0001] The utility model relates to cement production equipment, in particular to a system integrating thermal power generation and cement production. Background Art

[0002] Fuel refers to combustible substances. According to the state of the substance, it can be divided into: solid fuel, such as coal, oil shale and coke, the product of coal processing; liquid fuel, such as petroleum and its processed products such as gasoline and diesel; gaseous fuel, such as coal gas and natural gas. According to the source, it can be divided into: natural fuel, such as coal, oil, natural gas, oil shale, etc.; artificial fuel or synthetic fuel, such as synthetic oil, synthetic gasoline, etc. In addition, there are nuclear fuels that use nuclear reactions to release huge heat. Fuel plays an important and indispensable role in industrial and agricultural production, transportation and people's lives. With the development of science and technology, mankind is developing and utilizing fuel more rationally and pursuing environmental protection as much as possible.

[0003] In the process of implementing the present utility model, the inventors found that there are at least the following problems in the prior art:

[0004] Coal gangue is a large-scale industrial solid waste. Its main components are Al2O3 and SiO2. In most cases, it has a certain calorific value. Directly discharging it or filling it back into the well will waste resources, occupy land, and cause air, water and soil pollution. If it is used directly to produce building materials, the spontaneous combustion of residual coal in the coal gangue, the ashification or decomposition of organic matter, and the mudification of soft rocks will have a great impact on the performance of cement. The current cement industry is facing huge pressure to reduce carbon emissions and needs to find a low-emission, high-activity cement clinker substitute.

[0005] Therefore, a system integrating thermal power generation and cement production is needed to at least partially solve the above technical problems. Utility Model Content

[0006] The present application provides a system integrating thermal power generation and cement production, which can realize power generation and cement production at the same time, and the generated flue gas can be reused.

[0007] The utility model provides a system integrating thermal power generation and cement production, the system comprising:

[0008] A vertical circulating fluidized bed boiler, the boiler comprising:

[0009] A material-to-be-calcined inlet, at least one fuel feed inlet, an air inlet and a slag discharge inlet are arranged at the bottom; wherein the material-to-be-calcined inlet is used to feed the material to be calcined, and the slag discharge inlet is used to discharge the product after calcination of the material to be calcined fed into the boiler;

[0010] A flue gas duct is provided to the top for conducting the flue gas generated by the boiler; and

[0011] A circulating gas inlet provided to the middle portion;

[0012] An air duct connected to the air inlet is used to introduce external air, and both the air duct and the flue gas duct pass through a heat exchanger to allow heat exchange between the air and the flue gas;

[0013] a circulating gas pipeline, one end of which is connected to the flue gas pipeline and the other end of which is connected to the circulating gas inlet, so as to return at least part of the flue gas to the boiler;

[0014] A steam generating device, connected to the furnace of the boiler, for generating steam;

[0015] a steam turbine connected to a steam generating device, the other end of the steam turbine being connected to a generator;

[0016] a slag cooler connected to the slag discharge port and used to cool the calcined product; and

[0017] Cement production line equipment for producing cement clinker;

[0018] Wherein, the slag cooler and the cement production line device are both connected to a cement mill so that the cooled calcined product is mixed and ground with the cement clinker to produce cement.

[0019] According to the system of the utility model, a circulating fluidized bed boiler is used as a combustion device to burn fuel and calcine the material to be calcined. The heat generated during combustion heats the steam generating device to generate steam, and the steam drives the steam turbine and the generator to rotate and generate electricity. The high-temperature flue gas generated during combustion first heats the air, so that the air entering the boiler has a higher temperature, reducing energy consumption. The flue gas after heat exchange returns to the boiler, which can reduce the local high temperature in the boiler on the one hand, and on the other hand, because the flue gas contains a high concentration of reducing gas (such as CO), a reducing atmosphere can be formed in the boiler, ensuring that the material to be calcined is calcined in a reducing atmosphere, and the generation of NOx can be suppressed. The calcined product is cooled by a slag cooler and mixed and ground with other cement clinker produced by the cement production line device to produce cement. The system of the utility model realizes power generation and cement production at the same time, and the generated flue gas is reused.

[0020] Optionally, the at least one fuel feed inlet comprises:

[0021] A first fuel feeding port, used for feeding fossil fuel;

[0022] The second fuel feeding port is used to feed alternative fuel.

[0023] Optionally, the material fed into the inlet for materials to be calcined is coal gangue, and the inlet for materials to be calcined is also connected to a mill via a conveying pipeline to crush and grind the coal gangue.

[0024] Optionally, a waste gas treatment device is further provided on the flue gas pipeline, including a desulfurization device, a denitrification device and / or a dust removal device, and the other end of the waste gas treatment device is connected to the chimney;

[0025] The circulating gas duct is connected to the flue gas duct at a position between the exhaust gas treatment device and the chimney.

[0026] Optionally, the cement production line device is also connected to the chimney to share the same chimney for smoke exhaust.

[0027] Optionally, the slag cooler is further connected to a storage bin via a conveying device for storage, and the storage bin is connected to the cement mill. And / or

[0028] The generator is also connected to the cement production line device to provide electricity.

[0029] According to this solution, the electricity generated by the generator can be directly used for the operation of the cement production line equipment, reducing operating costs and reducing carbon emissions caused by purchasing electricity.

[0030] By utilizing the technical solution according to the embodiment of the utility model, the beneficial effects that can be obtained are at least:

[0031] According to the system of the utility model, a circulating fluidized bed boiler is used as a combustion device to burn fuel and calcine the material to be calcined. The heat generated during the combustion heats the steam generating device to generate steam, and the steam drives the steam turbine and the generator to rotate and generate electricity. The high-temperature flue gas generated during the combustion first heats the air, so that the air entering the boiler has a higher temperature, thereby reducing energy consumption. The flue gas after heat exchange returns to the boiler, which can reduce the local high temperature in the boiler. At the same time, since the flue gas contains a higher concentration of reducing gas (such as CO), a reducing atmosphere can be formed in the boiler, ensuring that the material to be calcined is calcined in a reducing atmosphere, and the generation of NOx can be suppressed. The calcined product is cooled by a slag cooler and then mixed and ground with other cement clinker produced by the cement production line device to produce cement.

[0032] Additional advantages, purposes, and features of the present invention will be partially described in the following description, and will become partially apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The purposes and other advantages of the present invention can be achieved and obtained by the structures specifically pointed out in the specification and the drawings.

[0033] Those skilled in the art will understand that the purposes and advantages that can be achieved by the present invention are not limited to the above specific description, and the above and other purposes that can be achieved by the present invention will be more clearly understood based on the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present invention, and do not constitute a limitation of the present invention. The components in the drawings are not drawn to scale, but are only for the purpose of illustrating the principles of the present invention. In order to facilitate the illustration and description of some parts of the present invention, the corresponding parts in the drawings may be enlarged, that is, they may become larger relative to other components in the exemplary device actually manufactured according to the present invention.

[0035] In the attached picture:

[0036] Figure 1 The figure is an overall schematic diagram of a system integrating thermal power generation and cement production according to an embodiment of the utility model.

[0037] Description of reference numerals:

[0038] 100: system;

[0039] 110: Circulating fluidized bed boiler;

[0040] 111: inlet for feeding materials to be calcined;

[0041] 112: first fuel feeding port;

[0042] 113: second fuel feeding port;

[0043] 114: air inlet;

[0044] 115: slag discharge port;

[0045] 116: Flue gas duct;

[0046] 117: circulating gas inlet;

[0047] 120: air duct;

[0048] 130: Circulating gas pipeline;

[0049] 141: Steam turbine;

[0050] 142: generator;

[0051] 150: slag cooler;

[0052] 160: Cement production line device;

[0053] 171: dust collector;

[0054] 172: Chimney;

[0055] 173: Heat exchanger. DETAILED DESCRIPTION

[0056] By referring to the exemplary embodiments, the purposes and functions of the present invention and the methods for achieving these purposes and functions will be explained. However, the present invention is not limited to the exemplary embodiments disclosed below; it can be implemented in different forms. The essence of the description is only to help technicians in the relevant field to comprehensively understand the specific details of the present invention.

[0057] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0058] Ordinal numbers such as "first" and "second" cited in the present invention are merely identifiers and do not have any other meanings, such as a specific order, etc. Moreover, for example, the term "first component" itself does not imply the existence of the "second component", and the term "second component" itself does not imply the existence of the "first component".

[0059] It should be noted that the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside" and similar expressions used in this document are for illustrative purposes only and are not limiting.

[0060] The utility model provides a system 100 integrating thermal power generation and cement production. The system 100 can be applied to cement production equipment, such as the cement production industry to generate electricity while producing cement, and to recycle the generated flue gas in various aspects.

[0061] Among them, there are many types of materials to be calcined. Taking the cement production industry as an example, the materials to be calcined include various clay minerals, gypsum and coal gangue.

[0062] The main components of coal gangue are Al2O3 and SiO2, which have a certain calorific value in most cases. Directly discharging or filling it back into the well will waste resources, occupy land, and cause air, water and soil pollution. If it is used directly to produce building materials (such as cement), the spontaneous combustion of residual coal in the coal gangue, the ashification or decomposition of organic matter, and the mudification of soft rocks will have a great impact on the performance of cement. Among them, coal gangue can provide part of the heat, and the calcined material has gelling activity, which can replace part of the cement clinker and mix with cement clinker, limestone, gypsum, etc. to produce LC 3 Cement. LC 3 Compared with ordinary Portland cement, cement can reduce carbon emission intensity by 40%, accelerating the process of carbon neutrality in the cement industry. In order to achieve the rational use of coal gangue, the system 100 of the utility model is applied to the production of low-carbon LC 3 Cement is a specific example and is not intended to be limiting. The cement may also be applied to other materials to be calcined to produce other types of cement.

[0063] The utility model provides a system 100 integrating thermal power generation and cement production. In a preferred embodiment, Figure 1 As shown, the system 100 includes a circulating fluidized bed boiler 110, an air duct 120, a circulating gas duct 130, a steam generator, a generator 142, a slag cooler 150 and a cement production line device 160. The circulating fluidized bed boiler 110 is used as a combustion device for fuel combustion and coal gangue calcination. The air duct 120 is used to introduce heated air into the boiler. The circulating gas duct 130 is used to return the flue gas generated by the boiler to the boiler for reuse. The steam generator is used to generate steam with the heat generated by the boiler combustion. The generator 142 is used to generate electricity. The slag cooler 150 is used to cool the product after the coal gangue is calcined. The cement production line device 160 is used to cooperate with the product after the coal gangue is calcined to achieve cement production.

[0064] refer to Figure 1 In the illustrated embodiment, the circulating fluidized bed boiler 110 is vertically arranged. As a combustion device with a relatively superior combustion effect, it is a prior art product and will not be described in detail here.

[0065] Furthermore, the boiler includes a material inlet 111 for calcining, at least one fuel inlet, an air inlet 114 and a slag outlet 115 arranged at the bottom. The material inlet 111 for calcining is used to feed coal gangue. The slag outlet 115 is used to discharge the calcined product of the coal gangue fed into the boiler.

[0066] In order to reduce the use of traditional fossil fuels and reduce carbon emissions, preferably, the fuel feed port may include a first fuel feed port 112 and a second fuel feed port 113. The first fuel feed port 112 is used to feed fossil fuels, such as coal and natural gas. The second fuel feed port 113 is used to feed alternative fuels. The circulating fluidized bed boiler 110 can be ignited using traditional fossil fuels such as coal or natural gas, and after the furnace temperature reaches 850-900°C and runs stably, alternative fuels are then added to reduce the use of traditional fossil fuels.

[0067] The boiler also includes a flue gas duct 116 disposed at the top and a circulating gas inlet 117 disposed at the middle portion. The flue gas duct 116 is used to guide the flue gas generated by the boiler. The flue gas generated by the boiler has a high temperature and contains a high concentration of reducing gas (such as CO). The middle portion generally refers to the portion between the bottom and the top of the boiler. The circulating gas inlet 117 can be reasonably set according to actual needs, and the number can be one or more.

[0068] The air duct 120 is used to introduce external air and is connected to the air inlet 114. The air duct 120 and the flue gas duct 116 both pass through the heat exchanger 173 to allow the air to exchange heat with the flue gas generated by the combustion of the boiler, so that the air entering the boiler has a higher temperature initially. The heat exchanger 173 can be an air-to-air heat exchanger (air heat exchanger).

[0069] One end of the circulating gas pipeline 130 is connected to the flue gas pipeline 116, and the other end is connected to the circulating gas inlet 117, so as to return at least part of the flue gas to the boiler. The flue gas circulating into the boiler has a lower temperature due to heat exchange.

[0070] A steam generating device is connected to the furnace of the boiler and is used to generate steam; wherein the steam generating device adopts a prior art device, and its specific form or structure is not the innovative point to be protected by the present utility model and will not be described in detail here.

[0071] The steam turbine 141 connected to the steam generating device rotates by using the steam generated by the steam generating device, thereby operating the generator 142 to generate electricity.

[0072] The slag cooler 150 is connected to the slag discharge port 115 and is used to cool the calcined product. Generally speaking, the temperature of the calcined product is 850-900°C. The slag cooler 150 uses dry slag indirect water heat exchange. First, the calcined product can be quickly cooled to about 100°C, which can solve the color change problem caused by the high iron content in the coal gangue and make the produced LC 3 The appearance of cement is consistent with that of ordinary cement; secondly, the water after heat exchange enters the steam generating device, thus avoiding heat loss.

[0073] The cement production line device 160 is used to produce cement clinker. The cement production line device 160 adopts the existing technology device, and its specific form or structure is not the innovation point to be protected by the utility model, and is not described additionally here.

[0074] The slag cooler 150 and the cement production line device 160 are both connected to the cement mill so that the cooled calcined product is mixed and ground with the cement clinker to produce cement.

[0075] Based on the above scheme, the circulating fluidized bed boiler 110 is used as the combustion equipment to burn the fuel and calcine the material to be calcined. The heat generated during the combustion heats the steam generating device to generate steam, and the steam drives the steam turbine 141 and the generator 142 to rotate and generate electricity. The high-temperature flue gas generated during the combustion first heats the air, so that the air entering the boiler has a higher temperature, reducing energy consumption. The flue gas after heat exchange returns to the boiler, which can reduce the local high temperature in the boiler on the one hand, and on the other hand, because the flue gas contains a high concentration of reducing gas (such as CO), a reducing atmosphere can be formed in the boiler, ensuring that the material to be calcined is calcined in a reducing atmosphere, and the generation of NOx can be suppressed. The calcined product is cooled by the slag cooler 150 and then mixed and ground with other cement clinker produced by the cement production line device 160 to produce LC 3 cement.

[0076] For example, a thermal power plant consisting of a steam turbine 141, a generator 142, etc. is built adjacent to a cement production line device 160. The thermal power plant uses alternative fuels as the main heat source and uses a circulating fluidized bed boiler 110 to enhance its combustion effect. The residual heat in the boiler will be used to heat water vapor, driving the steam turbine 141 and the generator 142 to rotate and generate electricity. The generator 142 can also be connected to the cement production line device 160 to provide electricity, reducing the cost of purchasing electricity for the cement production line, and at the same time, the surplus electricity is connected to the grid to bring additional income.

[0077] According to the system 100 of the utility model, power generation and cement production can be achieved simultaneously, and the generated flue gas can be reused.

[0078] In a preferred embodiment, the calcined material inlet 111 is also connected to a mill via a conveying pipeline to crush and grind the gangue, for example, crushing and grinding the gangue to 0-5 mm, and then conveying it to the circulating fluidized bed boiler 110 for calcination via a pipeline to improve the calcination effect of the gangue.

[0079] Continue to refer Figure 1 A dust collector 171 is also provided on the flue gas duct 116, and the other end of the dust collector 171 is connected to the chimney 172. The circulating gas duct 130 is connected to the flue gas duct 116 at a position between the dust collector 171 and the chimney 172.

[0080] It can be understood that the dust collector 171 is only a specific embodiment. As a waste gas treatment device, the dust collector 171 can also be replaced with other waste gas treatment devices or combinations to perform various treatments on the flue gas, such as desulfurization, denitrification, water removal, dust removal and / or cooling.

[0081] In order to arrange the space reasonably and save costs, the cement production line device 160 can also be connected to the chimney 172 to share the same chimney 172 for smoke exhaust.

[0082] Furthermore, the slag cooler 150 can be connected to the storage bin via a conveying device (such as a zipper machine) for storage. 3 cement.

[0083] In summary, according to the system 100 of the embodiment of the utility model, a circulating fluidized bed boiler 110 is used as the coal gangue calcining equipment, and an alternative fuel is used as the fuel, and the calcined material is used to produce LC 3 cement, increasing the output of low-carbon products in the plant; and LC 3 The performance of cement is close to that of ordinary silicate cement, and the carbon dioxide emission per unit product is reduced by 40%, which can accelerate the carbon neutrality process of the cement industry; at the same time, it solves the problem of urban garbage, reduces the purchase of electricity for the plant, and reduces the production and operation costs; the flue gas generated by the boiler is circulated into the circulating fluidized bed boiler 110, and a reducing atmosphere can be formed in the boiler to ensure that the coal gangue is calcined in a reducing atmosphere, and the slag cooler 150 can quickly cool the high-temperature material, and at the same time, the hot water is circulated back to the steam generating device to avoid the heat loss of the cooling water. Multiple measures are taken to solve the color change problem caused by the excessive iron content in the coal gangue, so that the produced LC 3 The appearance of cement is the same as ordinary cement.

[0084] In combination with the description and practice of the utility model disclosed herein, other embodiments of the utility model are easy to think of and understand for those skilled in the art. The description and embodiments are considered to be exemplary only, and the true scope and spirit of the utility model are defined by the claims.

Claims

1. A system integrating thermal power generation and cement production, characterized in that: The system comprises: A vertical circulating fluidized bed boiler, the boiler comprising: A material-to-be-calcined inlet, at least one fuel feed inlet, an air inlet and a slag discharge inlet are arranged at the bottom; wherein the material-to-be-calcined inlet is used to feed the material to be calcined, and the slag discharge inlet is used to discharge the product after calcination of the material to be calcined fed into the boiler; A flue gas duct is provided to the top for conducting the flue gas generated by the boiler; and A circulating gas inlet provided to the middle portion; An air duct connected to the air inlet is used to introduce external air, and both the air duct and the flue gas duct pass through a heat exchanger to allow heat exchange between the air and the flue gas; a circulating gas pipeline, one end of which is connected to the flue gas pipeline and the other end of which is connected to the circulating gas inlet, so as to return at least part of the flue gas to the boiler; A steam generating device, connected to the furnace of the boiler, for generating steam; a steam turbine connected to a steam generating device, the other end of the steam turbine being connected to a generator; a slag cooler connected to the slag discharge port and used to cool the calcined product; and Cement production line equipment for producing cement clinker; Wherein, the slag cooler and the cement production line device are both connected to a cement mill so that the cooled calcined product is mixed and ground with the cement clinker to produce cement.

2. The system according to claim 1, characterized in that The at least one fuel feed inlet comprises: A first fuel feeding port, used for feeding fossil fuel; The second fuel feeding port is used to feed alternative fuel.

3. The system according to claim 2, characterized in that The material fed into the inlet for materials to be calcined is coal gangue, and the inlet for materials to be calcined is also connected to a mill via a conveying pipeline to crush and grind the coal gangue.

4. The system according to claim 1, 2 or 3, characterized in that: The flue gas pipeline is also provided with an exhaust gas treatment device, including a desulfurization device, a denitrification device and / or a dust removal device, and the other end of the exhaust gas treatment device is connected to the chimney; The circulating gas duct is connected to the flue gas duct at a position between the exhaust gas treatment device and the chimney.

5. The system according to claim 4, characterized in that The cement production line device is also connected to the chimney to share the same chimney for smoke exhaust.

6. The system according to claim 1 or 5, characterized in that: The slag cooler is also connected to a storage bin via a conveying device to store the calcined product, and the storage bin is connected to the cement mill; and / or The generator is also connected to the cement production line device to provide electricity.

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