Blending combustion dealkalized biomass system of pulverized coal boiler

Abstract

The invention discloses a pulverized coal fired boiler blending combustion dealkalized biomass system, which comprises a hydrothermal assembly, a pulverized coal fired boiler blending combustion dealkalized biomass system, a pulverized coal fired boiler blending combustion dealkalized biomass system and a pulverized coal fired boiler blending combustion dealkalized biomass system, and is characterized in that the hydrothermal assembly is provided with a heating piece and is used for heating a mixture of biomass and water in the hydrothermal assembly; the feeding end of the dehydration equipment is connected with the discharging end of the hydrothermal assembly, the dehydration equipment is used for carrying out dehydration treatment on the mixture of the biomass and the water, and the separated water flows out of a water outlet of the dehydration equipment; the feeding end of the drying machine is connected with the biomass outlet of the dehydration equipment, and the drying machine is used for drying the biomass; the feeding end of the coal mill is connected with the discharging end of the drying machine, and the coal mill is used for mixing and grinding biomass and coal; and the feeding end of the boiler is connected with the discharging end of the coal mill, and the boiler is used for mixing and combusting the mixture of the biomass and the coal. According to the pulverized coal boiler blending combustion dealkalization biomass system, hydrothermal dealkalization / alkaline earth metal treatment can be carried out on biomass, and the slagging problem in the blending combustion process is prevented.

Description

Technical Field

[0001] The invention relates to the technical field of pulverized coal boiler co-firing, and in particular to a pulverized coal boiler co-firing dealkalized biomass system. Background Art

[0002] The combustion of biomass in pulverized coal boilers is a low-carbon combustion technology that the country is currently vigorously promoting. Biomass is a zero-carbon fuel, and the combustion of biomass helps to achieve the dual carbon goals. However, biomass has a high content of alkali / alkaline earth metals. During the combustion process, the alkali / alkaline earth metals will evaporate into the gas phase. As the flue gas temperature decreases, they will adhere to the heating surface, causing the risk of slagging. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a pulverized coal boiler co-combustion dealkalization biomass system, which can perform hydrothermal dealkalization / alkaline earth metal treatment on biomass to prevent slagging during the co-combustion of biomass.

[0004] The pulverized coal boiler co-combustion dealkalizing biomass system according to an embodiment of the present invention comprises: a hydrothermal component, wherein the hydrothermal component has a heating element for heating a mixture of biomass and water in the hydrothermal component; a dehydration device, wherein the feed end of the dehydration device is connected to the discharge end of the hydrothermal component and is used to dehydrate the mixture of biomass and water, and the dehydrated water flows out from the water outlet of the dehydration device; a dryer, wherein the feed end of the dryer is connected to the biomass outlet of the dehydration device and is used to dry the biomass; a coal mill, wherein the feed end of the coal mill is connected to the discharge end of the dryer and is used to mix and grind the biomass and coal; and a boiler, wherein the feed end of the boiler is connected to the discharge end of the coal mill and is used to mix and burn the mixture of biomass and coal.

[0005] The pulverized coal boiler co-combustion dealkalizing biomass system according to the embodiment of the present invention is provided with a hydrothermal component, a dehydration device, a dryer, a coal mill and a boiler, so that the biomass can be hydrothermally dealkalized / alkaline earth metal treated before drying the biomass, thereby achieving a large proportion of biomass co-combustion and preventing slagging problems from occurring during the co-combustion of biomass, thereby ensuring the output and efficiency of the boiler, reducing fuel consumption and operating costs, ensuring the safe operation of the boiler, and relatively extending the service life of the pulverized coal boiler co-combustion dealkalizing biomass system.

[0006] In addition, the pulverized coal boiler co-combustion dealkalized biomass system according to the present invention may also have the following additional technical features:

[0007] In some embodiments, the hydrothermal component includes: a hydrothermal reactor, the discharge end of which is connected to the feed end of the dehydration device; and a heat pump component, a portion of which is located in the hydrothermal reactor to form the heating element.

[0008] In some embodiments, the heat pump assembly includes: a heat pump body; a first circuit, part of which is located in the heat pump body and part of which is located in the hydrothermal reactor to form the heating element; a first flow path, part of which is located in the heat pump body, and both ends of the first flow path in the extension direction are connected to the tail flue of the boiler; a second flow path, part of which is located in the heat pump body, and one end of the second flow path in the extension direction is connected to the water outlet of the dehydration equipment.

[0009] In some embodiments, the pulverized coal boiler co-combustion dealkalizing biomass system further includes: a water treatment unit, wherein the inlet of the water treatment unit is connected to the outlet of the dehydration equipment, and the outlet of the water treatment unit is connected to the hydrothermal reactor.

[0010] In some embodiments, the reaction temperature of the hydrothermal reactor is 60-100°C.

[0011] In some embodiments, the pulverized coal boiler co-combustion dealkalizing biomass system further includes: a silo, the feed end of which is connected to the discharge end of the dryer, and the discharge end of which is connected to the feed end of the coal mill, for accommodating the dried biomass.

[0012] In some embodiments, the dryer has an air inlet and an air outlet, the air inlet is connected to the tail flue of the boiler, and the air outlet is connected to the boiler.

[0013] In some embodiments, the dehydration equipment is a screw extrusion dehydrator.

[0014] In some embodiments, the boiler is a W-type flame boiler.

[0015] In some embodiments, the feed end of the boiler has a burner, and the burner is connected to the discharge end of the coal mill to feed the mixture of ground biomass and coal into the boiler for combustion.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0018] Figure 1 It is a structural schematic diagram of a pulverized coal boiler co-firing dealkalized biomass system according to an embodiment of the present invention.

[0019] Reference numerals:

[0020] 100. Pulverized coal boiler mixed combustion de-alkali biomass system;

[0021] 1. hydrothermal component; 10. heating element; 11. hydrothermal reactor; 12. heat pump component; 121. heat pump body; 122. first circuit; 123. first flow path; 124. second flow path;

[0022] 2. Dehydration equipment; 21. Water outlet; 22. Biomass outlet;

[0023] 3. Dryer; 31. Air inlet; 32. Air outlet;

[0024] 4. Coal mill;

[0025] 5. Boiler; 50. Tail flue; 51. Combustion chamber; 52. Cooling chamber; 53. Burner;

[0026] 6. Silo. DETAILED DESCRIPTION

[0027] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] The following describes a pulverized coal boiler co-firing dealkalized biomass system 100 according to an embodiment of the present invention with reference to the accompanying drawings.

[0032] like Figure 1 As shown, the pulverized coal boiler co-combustion dealkalizing biomass system 100 according to an embodiment of the present invention includes a hydrothermal component 1, a dehydration device 2, a dryer 3, a coal mill 4 and a boiler 5.

[0033] Specifically, refer to the attached Figure 1 As shown, the hydrothermal component 1 has a heating element 10 for heating the mixture of biomass and water in the hydrothermal component 1. The heating element 10 can create a high-temperature and high-pressure hydrothermal environment, and after the biomass and water are mixed in a certain proportion, a thermochemical reaction occurs between the biomass and the water. Furthermore, the feed end of the dehydration device 2 is connected to the discharge end of the hydrothermal component 1, and is used to dehydrate the mixture of biomass and water. The dehydrated water flows out from the water outlet 21 of the dehydration device 2. The water flowing out from the water outlet 21 of the dehydration device 2 can directly flow out of the pulverized coal boiler co-combustion dealkalization biomass system 100, or it can flow back to the hydrothermal component 1 after being treated.

[0034] It can be understood that in a high-temperature and high-pressure hydrothermal environment, biomass is mixed with water, and water is used as a reaction medium, so that some water-soluble and acetic acid-soluble alkali / alkaline earth metals are removed from the biomass and enter the water, and then the water is separated from the mixture of biomass and water through dehydration treatment by the dehydration equipment 2, thereby realizing the hydrothermal dealka / alkaline earth metal removal of biomass.

[0035] Further, see Appendix Figure 1 As shown, the feed end of the dryer 3 is connected to the biomass outlet 22 of the dehydration device 2, and is used to dry the biomass. After drying, the moisture and volatile matter of the biomass molded fuel are separated, the calorific value is greatly improved, and the energy density of the biomass is greatly improved. Furthermore, the feed end of the coal mill 4 is connected to the discharge end of the dryer 3, and is used to mix and grind the biomass with coal. After drying, the fibrous structure in the biomass is destroyed, and the brittleness is greatly improved, so that the changed biomass can be ground using the existing coal mill 4.

[0036] Further, see Attachment Figure 1 As shown, the feed end of the boiler 5 is connected to the discharge end of the coal mill 4, which is used to mix and burn the mixture of biomass and coal. Since the existing pulverizing system is used to directly mix the biomass, there is no need to modify the existing boiler 5. The existing boiler 5 can be directly used, avoiding the modification of the boiler 5 and reducing the workload of equipment modification.

[0037] It can be understood that the biomass A and water are first introduced into the hydrothermal component 1 for mixing. Under the heating of the heating element 10, the biomass A reacts with the water, and a mixture B of biomass and water flows out from the discharge port of the hydrothermal component 1. The mixture B of biomass and water enters the dehydration device 2 from the feed end of the dehydration device 2. The dehydration device 2 dehydrates the mixture B of biomass and water, and obtains biomass C after the water is discharged. The biomass C flows out from the biomass outlet 22 of the dehydration device 2 and enters the dryer 3 from the feed end of the dryer 3. Biomass D is obtained under the drying treatment of the dryer 3. The biomass D and coal are added into the pulverizer 4 together, and the mixture of biomass D and coal is ground. Finally, the mixture E of biomass and coal is transported to the boiler 5, and the mixture E of biomass and coal is mixed and burned.

[0038] It should be noted that biomass mainly refers to materials such as straw, trees and other wood cellulose (lignin for short) in the agricultural and forestry production process, waste materials from agricultural and forestry processing, and livestock manure and waste in the animal husbandry production process, except for grain and fruit. Biomass energy is an important component of renewable energy. The efficient development and utilization of biomass energy will play a very positive role in solving energy and ecological environmental problems. Biomass co-combustion is an effective way and important means to reduce carbon dioxide emissions.

[0039] In the prior art, due to the high content of alkali / alkaline earth metals in biomass, alkali / alkaline earth metals will volatilize into the gas phase during the combustion process. As the flue gas temperature decreases, they will adhere to the heating surface, causing the risk of slagging, thereby leading to reduced boiler output and efficiency, increased fuel consumption and operating costs, inability to operate the boiler safely, shortened equipment service life, and other problems. The present invention removes water-soluble and acetic acid-soluble alkali / alkaline earth metals in biomass through a hydrothermal method, achieves large-scale blending of biomass, and prevents slagging problems from occurring during blending of biomass, thereby ensuring the output and efficiency of the boiler 5, reducing fuel consumption and operating costs, ensuring the safe operation of the boiler 5, and relatively extending the service life of the pulverized coal boiler blending dealkalization biomass system 100.

[0040] According to the pulverized coal boiler co-combustion dealkalization biomass system 100 of the embodiment of the present invention, by providing a hydrothermal component 1, a dehydration device 2, a dryer 3, a pulverizer 4 and a boiler 5, the biomass can be hydrothermally dealkalized / alkaline earth metal treated before drying the biomass, thereby achieving a large proportion of biomass co-combustion and preventing slagging problems from occurring during the co-combustion of biomass, thereby ensuring the output and efficiency of the boiler 5, reducing fuel consumption and operating costs, ensuring the safe operation of the boiler 5, and relatively extending the service life of the pulverized coal boiler co-combustion dealkalization biomass system 100.

[0041] In some embodiments of the present invention, Figure 1 As shown, the hydrothermal component 1 includes a hydrothermal reactor 11 and a heat pump component 12. The discharge end of the hydrothermal reactor 11 is connected to the feed end of the dehydration device 2. The biomass and water are mixed in the hydrothermal reactor 11. The heat pump component 12 is a device that transfers heat energy from a low-level heat source to a high-level heat source. It can force heat to flow from a low-temperature object to a high-temperature object through a reverse cycle. Part of the heat pump component 12 is located in the hydrothermal reactor 11 to form a heating element 10, which can form a high-temperature and high-pressure hydrothermal environment in the hydrothermal reactor 11, so that the biomass and water can be better mixed.

[0042] In a further embodiment of the present invention, referring to the attached Figure 1 As shown, the heat pump assembly 12 includes a heat pump body 121, a first loop 122, a first flow path 123 and a second flow path 124. Part of the first loop 122 is located in the heat pump body 121, and part of it is located in the hydrothermal reactor 11 to form a heating element 10. Part of the first flow path 123 is located in the heat pump body 121, and both ends of the first flow path 123 in the extension direction are connected to the tail flue 50 of the boiler 5. Part of the second flow path 124 is located in the heat pump body 121, and one end of the second flow path 124 in the extension direction is connected to the water outlet 21 of the dehydration equipment 2.

[0043] It can be understood that part of the medium-temperature flue gas in the tail flue 50 is extracted and guided to the heat pump body 121 along the first flow path 123, so that it serves as a driving heat source for the heat pump body 121 to drive the heat pump body 121 to operate. After releasing heat, the flue gas returns to the tail flue 50 along the first flow path 123. The hot water flowing out of the water outlet 21 of the dehydration equipment 2 is a low-temperature heat source. It flows from the water outlet 21 to the heat pump body 121 through the second flow path 124, and exchanges heat with the water in the first loop 122 in the heat pump body 121. The hot water generated by the heat pump body 121 enters the hydrothermal reactor 11 through the first loop 122 to release heat, and then returns to the heat pump body 121 along the first loop 122 to continue absorbing heat.

[0044] In a further embodiment of the present invention, the pulverized coal boiler co-combustion dealkalizing biomass system 100 also includes a water treatment unit, the inlet of the water treatment unit is connected to the outlet 21 of the dehydration equipment 2, and the outlet of the water treatment unit is connected to the hydrothermal reactor 11. The setting of the water treatment unit can treat the water flowing out of the outlet 21 of the dehydration equipment 2 to remove impurities such as alkali / alkaline earth metals in the water. The treated water can flow to the hydrothermal reactor 11 again to achieve recycling.

[0045] It should be noted that the hot water flowing out from the water outlet 21 of the dehydration device 2 can first flow to the heat pump body 121, and then flow to the water treatment unit after heat exchange with the water in the first loop 122, thereby fully utilizing the heat of the hot water flowing out from the water outlet 21 of the dehydration device 2.

[0046] In a further embodiment of the present invention, the reaction temperature of the hydrothermal reactor 11 is 60-100°C, which can reduce the energy consumption of the hydrothermal reactor 11 as much as possible while ensuring the effective separation of water-soluble and acetic acid-soluble alkali / alkaline earth metals in the biomass, thereby reducing the overall energy consumption of the pulverized coal boiler co-combustion dealkalization biomass system 100. For example, the reaction temperature of the hydrothermal reactor 11 can be 60°C, 70°C, 80°C, 90°C or 100°C.

[0047] In some embodiments of the present invention, Figure 1 As shown, the pulverized coal boiler co-combustion dealkalizing biomass system 100 also includes a silo 6, the feed end of the silo 6 is connected to the discharge end of the dryer 3, and the discharge end of the silo 6 is connected to the feed end of the coal mill 4, for accommodating the dried biomass. The setting of the silo 6 can store the biomass flowing out of the discharge end of the dryer 3, ensure the continuity of the biomass flowing to the coal mill 4, ensure the supply of biomass, and ensure the continuity and stability of the production of the pulverized coal boiler co-combustion dealkalizing biomass system 100.

[0048] In some embodiments of the present invention, Figure 1 As shown, the dryer 3 has an air inlet 31 and an air outlet 32. The air inlet 31 is connected to the tail flue 50 of the boiler 5, and the air outlet 32 ​​is connected to the boiler 5. Part of the flue gas in the tail flue 50 can enter the dryer 3 through the air inlet 31, and the flue gas drying of the biomass is achieved by directly contacting the biomass. The heat energy of the flue gas can be used to achieve the purpose of drying. The flue gas drying has the advantages of high efficiency, energy saving, environmental protection and emission reduction, and the high-temperature flue gas can heat the biomass evenly and quickly, so that the moisture in the biomass evaporates quickly, achieving an ideal drying effect, and ensuring the quality of the biomass after drying.

[0049] In some embodiments of the present invention, the dehydration equipment 2 is a screw extrusion dehydrator, which has the advantages of strong dehydration capacity, energy saving and environmental protection, strong applicability, small footprint, easy installation, and simple operation. It can effectively dehydrate the mixture of biomass and water and significantly reduce the moisture content in the mixture of biomass and water.

[0050] In some embodiments of the present invention, Figure 1 As shown, the boiler 5 is a W-shaped flame boiler, and the boiler 5 includes a combustion chamber 51 and a cooling chamber 52. The combustion chamber 51 is located at the lower side of the cooling chamber 52. The volume of the combustion chamber 51 is greater than the volume of the cooling chamber 52. The feed end of the boiler 5 is arranged on the peripheral wall of the combustion chamber 51. The fuel combustion process is mainly carried out in the combustion chamber 51, which can improve the ignition stability, expand the load adjustment range, reduce slagging, and prolong the coal powder residence time, which is beneficial to the combustion of the mixed powder of biomass and coal.

[0051] In a further embodiment of the present invention, referring to the attached Figure 1 As shown, the feed end of the boiler 5 is provided with a burner 53, which is connected to the discharge end of the coal mill 4 and is used to feed the ground biomass and coal mixture into the boiler 5 for combustion. The setting of the burner 53 can expand the load adjustment range, improve the ignition stability, improve the combustion efficiency, prolong the coal powder residence time, and is conducive to the combustion of the mixed powder of biomass and coal.

[0052] Other structures and operations of the pulverized coal boiler co-combustion dealkalizing biomass system 100 according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0053] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0054] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A pulverized coal boiler mixed combustion dealkalized biomass system, characterized in that: include: a hydrothermal component, the hydrothermal component having a heating element for heating a mixture of biomass and water within the hydrothermal component; A dehydration device, wherein the feed end of the dehydration device is connected to the discharge end of the hydrothermal component, and is used to dehydrate the mixture of biomass and water, and the dehydrated water flows out from the water outlet of the dehydration device; A dryer, wherein the feed end of the dryer is connected to the biomass outlet of the dehydration device and is used for drying the biomass; A coal mill, the feed end of which is connected to the discharge end of the dryer, and is used to mix and grind the biomass and coal; A boiler, wherein the feed end of the boiler is connected to the discharge end of the coal mill, and is used for mixing and burning a mixture of biomass and coal.

2. The pulverized coal boiler co-combustion dealkalized biomass system according to claim 1, characterized in that: The hydrothermal component comprises: A hydrothermal reactor, wherein the discharge end of the hydrothermal reactor is connected to the feed end of the dehydration device; A heat pump assembly, a portion of which is located within the hydrothermal reactor to form the heating element.

3. The pulverized coal boiler co-combustion dealkalized biomass system according to claim 2, characterized in that: The heat pump assembly comprises: Heat pump body; a first loop, wherein a portion of the first loop is located in the heat pump body and a portion of the first loop is located in the hydrothermal reactor to form the heating element; a first flow path, wherein a portion of the first flow path is located in the heat pump body, and both ends of the first flow path in an extending direction are connected to the tail flue of the boiler; A second flow path, part of which is located in the heat pump body, and one end of the second flow path in an extending direction is connected to the water outlet of the dehydration device.

4. The pulverized coal boiler co-combustion dealkalized biomass system according to claim 2, characterized in that: The pulverized coal boiler mixed combustion dealkalized biomass system also includes: A water treatment unit, wherein the inlet of the water treatment unit is connected to the water outlet of the dehydration device, and the outlet of the water treatment unit is connected to the hydrothermal reactor.

5. The pulverized coal boiler co-combustion dealkalized biomass system according to claim 2, characterized in that: The reaction temperature of the hydrothermal reactor is 60-100°C.

6. The pulverized coal boiler co-combustion dealkalized biomass system according to claim 1, characterized in that: Also includes: A silo, wherein the feed end of the silo is connected to the discharge end of the dryer, and the discharge end of the silo is connected to the feed end of the coal mill, for containing the dried biomass.

7. The pulverized coal boiler co-combustion dealkalized biomass system according to claim 1, characterized in that: The dryer has an air inlet and an air outlet, wherein the air inlet is communicated with the tail flue of the boiler, and the air outlet is communicated with the boiler.

8. The pulverized coal boiler co-combustion dealkalized biomass system according to claim 1, characterized in that: The dehydration equipment is a screw extrusion dehydrator.

9. The pulverized coal boiler co-combustion dealkalized biomass system according to claim 1, characterized in that: The boiler is a W-shaped flame boiler.

10. The pulverized coal boiler co-combustion dealkalized biomass system according to claim 9, characterized in that: The feed end of the boiler is provided with a burner, and the burner is connected to the discharge end of the coal mill, and is used for feeding the mixture of ground biomass and coal into the boiler for combustion.

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