Boiler air and smoke system suitable for deep peak regulation and peak regulation method

Abstract

The invention relates to a boiler air and smoke system suitable for deep peak regulation and a peak regulation method. The boiler air and smoke system comprises an A-side air and smoke subsystem, a B-side air and smoke subsystem and an air supply communication valve pipe fitting. The A-side air and smoke subsystem comprises an A-side air pre-heater, an A-side primary air assembly, an A-side air supply assembly and an A-side smoke exhaust assembly. The A-side primary air assembly is connected with the A-side air supply assembly through a first A-side valve pipe fitting, and the A-side intersection of the first A-side valve pipe fitting and the A-side air supply assembly is further connected with the A-side adjacent furnace cold air supply mother pipe assembly. The B-side air and smoke subsystem comprises a B-side air pre-heater, a B-side primary air assembly, a B-side air supply assembly and a B-side smoke exhaust assembly; the B-side primary air assembly is connected with the B-side air supply assembly through a first B-side valve pipe fitting, and the B-side intersection of the first B-side valve pipe fitting and the B-side air supply assembly is further connected with the B-side adjacent furnace cold air supply mother pipe assembly; the air supply communication valve pipe fitting is communicated with the A-side air supply assembly and the B-side air supply assembly. The air supply device has the advantages of being stable in operation, low in energy consumption and environmentally friendly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal power unit peak shaving, in particular to a boiler air and flue gas system suitable for deep peak shaving and a peak shaving method. BACKGROUND

[0002] With the increasing proportion of renewable energy power generation in the energy structure, coal-fired power generation enterprises gradually transform from conventional main power to basic guarantee and system regulation power. Among them, coal power units, as the main unit equipment for current peak shaving auxiliary services, have fully participated in deep peak shaving and low load operation to effectively regulate the total load of the power grid. When coal power units participate in deep peak shaving, the power generation output is usually lower than 50% of the rated load, and the minimum can reach 25-30% of the rated load. The duration of deep peak shaving of some units accounts for one-third of the operating hours, and they are often in a long-term low-load operation state.

[0003] When the unit is in deep peak shaving and low load operation, the coal-fired power generation enterprise usually pays more attention to the reliability of the unit operation, that is, to avoid non-stop of the unit due to equipment failure or improper operation, and the economic efficiency of the unit operation is often ignored. For example, when some coal-fired power generation units are in low load operation, the air supply of the air supply fan is larger than the design of the fan body, the installation of the baffle door and the risk of surge, and the oxygen content of some boilers reaches 9-10% and above when the boiler is in operation. The heat loss of the flue gas system and the flue gas of the boiler increases the power consumption of the flue gas system and the flue gas of the boiler, and the high concentration of nitrogen oxides after conversion increases the ammonia injection amount and ammonia escape of the ammonia injection system.

[0004] That is, it is not difficult to understand that how to reduce the oxygen content and air volume of the boiler in low load operation of the coal power unit is the key to maintaining the energy-saving operation of the boiler air and flue gas system. However, the existing coal-fired boiler air and flue gas system is usually at a high energy consumption level due to the need to ensure the reliability of the unit operation and the limitation of the equipment itself, and is prone to increase the ammonia injection amount and ammonia escape of the unit. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the defects in the prior art and to provide a boiler air and flue gas system suitable for deep peak shaving and a peak shaving method.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical scheme: A boiler air and flue gas system suitable for deep peak shaving for supplying air to a boiler and exhausting flue gas from the boiler, comprising an A-side air and flue gas subsystem, a B-side air and flue gas subsystem, and an air supply communication valve pipe fitting; The A-side air and flue gas subsystem comprises an A-side air preheater, an A-side primary air assembly, an A-side air supply assembly and an A-side flue gas exhaust assembly which are in communication with the boiler through the A-side air preheater; the A-side primary air assembly and the A-side air supply assembly are connected through a first A-side valve pipe, and an A-side junction point between the first A-side valve pipe and the A-side air supply assembly is further connected with an A-side near-burner cold air supply mother pipe assembly; The B-side air and flue gas subsystem comprises a B-side air preheater, a B-side primary air assembly, a B-side air supply assembly and a B-side flue gas exhaust assembly which are in communication with the boiler through the B-side air preheater; the B-side primary air assembly and the B-side air supply assembly are connected through a first B-side valve pipe, and a B-side junction point between the first B-side valve pipe and the B-side air supply assembly is further connected with a B-side near-burner cold air supply mother pipe assembly; The air supply communication valve pipe connects the A-side air supply assembly and the B-side air supply assembly.

[0007] Preferably, a part of the A-side air supply assembly downstream of the A-side junction point is connected with the A-side near-burner cold air supply mother pipe assembly or the atmosphere through a second A-side valve pipe; and / or, A part of the B-side air supply assembly downstream of the B-side junction point is connected with the B-side near-burner cold air supply mother pipe assembly or the atmosphere through a second B-side valve pipe.

[0008] Preferably, the second A-side valve pipe comprises an A-side air supply and air exhaust electric valve and an A-side air supply and air exhaust electric regulating valve which are connected in series with each other; and / or, The second B-side valve pipe comprises a B-side air supply and air exhaust electric valve and a B-side air supply and air exhaust electric regulating valve which are connected in series with each other.

[0009] Preferably, the A-side near-burner cold air supply mother pipe assembly comprises an A-side near-burner cold air supply mother pipe, and an A-side near-burner electric valve and an A-side near-burner electric regulating valve which are connected in series between the A-side junction point and the A-side near-burner cold air supply mother pipe; and / or, The B-side near-burner cold air supply mother pipe assembly comprises a B-side near-burner cold air supply mother pipe, and a B-side near-burner electric valve and a B-side near-burner electric regulating valve which are connected in series between the B-side junction point and the B-side near-burner cold air supply mother pipe.

[0010] Preferably, the A-side primary air assembly comprises an A-side primary air fan, an A-side primary air fan outlet electric valve and an A-side primary air fan outlet electric regulating valve; The A-side air supply assembly comprises an A-side air supply fan and an A-side air supply fan outlet electric valve; The first A-side valve pipe is connected between the A-side primary air fan outlet electric valve and the A-side primary air fan outlet electric regulating valve at one end and connected downstream of the A-side air supply fan outlet electric valve at the other end. and / or, The B-side primary air assembly comprises a B-side primary air fan, a B-side primary air fan outlet electric valve and a B-side primary air fan outlet electric regulating valve. The B-side air supply assembly comprises a B-side air supply fan and a B-side air supply fan outlet electric valve. The first B-side valve pipe is connected between the B-side primary air fan outlet electric valve and the B-side primary air fan outlet electric regulating valve at one end and connected downstream of the B-side air supply fan outlet electric valve at the other end.

[0011] Preferably, the air supply communication valve pipe comprises a communication pipe and an air supply communication electric valve arranged on the communication pipe.

[0012] A peak shaving method for a boiler air and flue gas system suitable for deep peak shaving based on the above, comprising the following steps: Under a 20%-35% rated load condition, the A-side air supply assembly is shut down; The output of the B-side air supply assembly is increased to maintain the minimum specified air volume under the 20%-35% rated load condition; It is determined whether the B-side air supply assembly has a tripping fault, if not, the operation is maintained, if yes, the B-side air supply assembly is closed, the B-side temporary boiler cold air supply main assembly is opened, the first A-side valve pipe is opened, and the output of the A-side primary air assembly is increased to maintain the minimum specified air volume under the 20%-35% rated load condition; or, Under a 20%-35% rated load condition, the B-side air supply assembly is shut down; The output of the A-side air supply assembly is increased to maintain the minimum specified air volume under the 20%-35% rated load condition; It is determined whether the A-side air supply assembly has a tripping fault, if not, the operation is maintained, if yes, the A-side air supply assembly is closed, the A-side temporary boiler cold air supply main assembly is opened, the first B-side valve pipe is opened, and the output of the B-side primary air assembly is increased to maintain the minimum specified air volume under the 20%-35% rated load condition.

[0013] Preferably, the following steps are further included: When the unit is in a condition higher than 35% rated, the A-side primary air assembly, the A-side air supply assembly, the A-side flue gas exhaust assembly, the B-side primary air assembly, the B-side air supply assembly, the B-side flue gas exhaust assembly and the air supply communication valve pipe are opened, and the first A-side valve pipe, the A-side temporary boiler cold air supply main assembly, the second A-side valve pipe, the first B-side valve pipe, the B-side temporary boiler cold air supply main assembly and the second B-side valve pipe are closed.

[0014] A peak regulation method for a boiler air and flue gas system suitable for deep peak regulation based on the above, characterized in that it comprises the following steps: Under the 20%-35% rated load condition, the A-side air supply to air exhaust electric valve, the B-side air supply to air exhaust electric valve, the A-side air supply to air exhaust electric regulating valve and the B-side air supply to air exhaust electric regulating valve are opened, and the A-side air supply to air exhaust electric regulating valve and the B-side air supply to air exhaust electric regulating valve are synchronously regulated, so that part of the air is directly sent to the atmosphere, to maintain the minimum specified value of the air volume under the 20%-35% rated load condition.

[0015] A peak regulation method for a boiler air and flue gas system suitable for deep peak regulation based on the above, comprising the following steps: Under the 20%-35% rated load condition, the A-side air supply to air exhaust electric valve, the B-side air supply to air exhaust electric valve, the A-side air supply to air exhaust electric regulating valve and the B-side air supply to air exhaust electric regulating valve are opened, and the A-side air supply to air exhaust electric regulating valve and the B-side air supply to air exhaust electric regulating valve are synchronously regulated, so that part of the air volume is in series to the A-side air supply to air exhaust electric valve and the B-side air supply to air exhaust electric valve, to maintain the minimum specified value of the air volume under the 20%-35% rated load condition Compared with the prior art, the beneficial effects of the present application are: The application provides a boiler air and flue gas system suitable for deep peak regulation, wherein the first A-side valve pipe fitting is connected with the A-side primary air assembly and the A-side air supply assembly, meanwhile, the A-side intersection point of the first A-side valve pipe fitting and the A-side air supply assembly is also connected with the A-side temporary boiler cold air supply mother pipe assembly, so that the A-side primary air assembly and the A-side temporary boiler cold air supply mother pipe assembly can be used to realize the A-side air supply (i.e. secondary air supply) of the boiler under low working conditions. Similarly, the first B-side valve pipe fitting is connected with the B-side primary air assembly and the B-side air supply assembly, meanwhile, the B-side intersection point of the first B-side valve pipe fitting and the B-side air supply assembly is also connected with the B-side temporary boiler cold air supply mother pipe assembly, so that the B-side primary air assembly and the B-side temporary boiler cold air supply mother pipe assembly can be used to realize the B-side air supply (i.e. secondary air supply) of the boiler under low working conditions. Meanwhile, the air supply communication valve pipe fitting is connected with the A-side air supply assembly and the B-side air supply assembly, so that the A-side air and flue gas subsystem and the B-side air and flue gas subsystem can be matched with each other, so that the A-side air and flue gas subsystem and the B-side air and flue gas subsystem can be operated simultaneously to realize the A-side and B-side air supply of the boiler under normal working conditions, and when the low working condition is operated, the A-side air supply assembly is opened and the B-side air supply assembly is closed (or the A-side air supply assembly is closed and the B-side air supply assembly is opened), meanwhile, the A-side primary air assembly, the A-side temporary boiler cold air supply mother pipe assembly, the B-side primary air assembly and the B-side temporary boiler cold air supply mother pipe assembly are matched and adjusted, so that the stable operation of the unit equipment can be ensured under the low working condition, the energy consumption of the unit can be reduced, the ammonia injection amount and ammonia escape of the unit can be reduced, and the environmental protection and economy of the unit are improved. Correspondingly, based on the peak regulation method of the boiler air and flue gas system suitable for deep peak regulation, the stable operation of the unit equipment can be ensured under the low working condition, the energy consumption of the unit can be reduced, the ammonia injection amount and ammonia escape of the unit can be reduced, and the environmental protection and economy of the unit are improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the specific embodiments or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0017] Figure 1 A structural schematic diagram of the boiler air and flue gas system suitable for deep peak regulation is provided.

[0018] Figure 2 A structural schematic diagram of the boiler air and flue gas system suitable for deep peak regulation is provided. Figure 1 A structural schematic diagram of the boiler air and flue gas system suitable for deep peak regulation is provided.

[0019] Figure 3 Fig. 1 is a schematic diagram of a boiler air and flue gas system suitable for deep peak regulation in a first operating state. Figure 1 Fig. 2 is a schematic diagram of a boiler air and flue gas system suitable for deep peak regulation in a second operating state.

[0020] Figure 4 Fig. 3 is a schematic diagram of a boiler air and flue gas system suitable for deep peak regulation in a third operating state. Figure 1 Fig. 4 is a schematic diagram of a boiler air and flue gas system suitable for deep peak regulation in a fourth operating state.

[0021] Figure 5 Fig. 5 is a schematic diagram of a boiler air and flue gas system suitable for deep peak regulation in a fifth operating state. Figure 1 Fig. 6 is a schematic diagram of a boiler air and flue gas system suitable for deep peak regulation in a sixth operating state.

[0022] Figure 6 Fig. 7 is a schematic diagram of a boiler air and flue gas system suitable for deep peak regulation in a seventh operating state. Figure 1 Fig. 8 is a schematic diagram of a boiler air and flue gas system suitable for deep peak regulation in an eighth operating state.

[0023] BRIEF DESCRIPTION OF DRAWINGS 100, boiler; 1, A-side air and flue gas subsystem; 11, A-side air preheater; 12, A-side primary air assembly; 121, A-side primary air fan; 122, A-side primary air fan outlet motor valve; 123, A-side primary air fan outlet motor regulating valve; 13, A-side air supply assembly; 131, A-side air supply fan; 132, A-side air supply fan outlet motor valve; 14, A-side flue gas exhaust assembly; 15, first A-side valve piping; 151, A-side primary air supply branch motor valve; 152, A-side primary air supply branch motor regulating valve; 16, A-side near-boiler cold air supply header assembly; 160, A-side near-boiler cold air supply header; 161, A-side near-boiler motor valve; 162, A-side near-boiler motor regulating valve; 17, second A-side valve piping; 171, A-side air supply to air exhaust motor valve; 172, A-side air supply to air exhaust motor regulating valve; 2, B-side air and flue gas subsystem; 21, B-side air preheater; 22, B-side primary air assembly; 221, B-side primary air fan; 222, B-side primary air fan outlet motor valve; 223, B-side primary air fan outlet motor regulating valve; 23, B-side air supply assembly; 231, B-side air supply fan; 232, B-side air supply fan outlet motor valve; 24, B-side flue gas exhaust assembly; 25, first B-side valve piping; 251, B-side primary air supply branch motor valve; 252, B-side primary air supply branch motor regulating valve; 26, B-side near-boiler cold air supply header assembly; 260, B-side near-boiler cold air supply header; 261, B-side near-boiler motor valve; 262, B-side near-boiler motor regulating valve; 27, second B-side valve piping; 271, B-side air supply to air exhaust motor valve; 272, B-side air supply to air exhaust motor regulating valve; 3, air supply communication valve piping; 31, communication pipe; 32, air supply communication motor valve. DETAILED DESCRIPTION

[0024] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only part of, rather than all of, the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0025] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] Referring to Figures 1 to 6 The embodiment of the present application provides a boiler air and flue gas system suitable for deep peak regulation, which is used for air supply to a boiler 100 of a coal-fired power unit and flue gas discharge of the boiler 100. The boiler air and flue gas system comprises an A-side air and flue gas subsystem 1, a B-side air and flue gas subsystem 2 and an air supply communication valve pipe fitting 3, wherein the A-side air and flue gas subsystem 1 and the B-side air and flue gas subsystem 2 are used for air supply to the A side and the B side of the boiler 100, and the air supply communication valve pipe fitting 3 connects the A-side air and flue gas subsystem 1 and the B-side air and flue gas subsystem 2, so that the A-side air and flue gas subsystem 1 and the B-side air and flue gas subsystem 2 can cooperate with each other to realize uniform air supply to the boiler 100.

[0028] Specifically, the A-side air and flue gas sub-system 1 comprises an A-side air preheater 11, and an A-side primary air assembly 12, an A-side air supply assembly 13 and an A-side flue gas assembly 14 which are in communication with the boiler 100 through the A-side air preheater 11; the A-side primary air assembly 12 is connected with the A-side air supply assembly 13 through a first A-side valve pipe 15, and the A-side intersection point between the first A-side valve pipe 15 and the A-side air supply assembly 13 is further connected with an A-side near-burner cold air supply mother pipe assembly 16. The B-side air and flue gas sub-system 2 comprises a B-side air preheater 21, and a B-side primary air assembly 22, a B-side air supply assembly 23 and a B-side flue gas assembly 24 which are in communication with the boiler 100 through the B-side air preheater 21; the B-side primary air assembly 22 is connected with the B-side air supply assembly 23 through a first B-side valve pipe 25, and the B-side intersection point between the first B-side valve pipe 25 and the B-side air supply assembly 23 is further connected with a B-side near-burner cold air supply mother pipe assembly 26; an air supply communication valve pipe 3 is connected with the A-side air supply assembly 13 and the B-side air supply assembly 23.

[0029] It can be understood that, in the above scheme, the A-side primary air assembly 12 and the A-side air supply assembly 13 are connected through the first A-side valve pipe 15, and the A-side intersection point between the first A-side valve pipe 15 and the A-side air supply assembly 13 is further connected with the A-side near-burner cold air supply mother pipe assembly 16, so that in the low working condition, either one or both of the A-side primary air assembly 12 and the A-side near-burner cold air supply mother pipe assembly 16 can be used to replace the A-side air supply assembly 13 to realize the A-side air supply (i.e. to deliver the A-side secondary air) of the boiler 100. Similarly, the B-side primary air assembly 22 and the B-side air supply assembly 23 are connected through the first B-side valve pipe 25, and the B-side intersection point between the first B-side valve pipe 25 and the B-side air supply assembly 23 is further connected with the B-side near-burner cold air supply mother pipe assembly 26, so that in the low working condition, either one or both of the B-side primary air assembly 22 and the B-side near-burner cold air supply mother pipe assembly 26 can be used to replace the B-side air supply assembly 23 to realize the B-side air supply (i.e. to deliver the B-side secondary air) of the boiler 100.

[0030] Meanwhile, the A-side air supply assembly 13 and the B-side air supply assembly 23 are connected through the air supply connection valve pipe 3, the A-side air and smoke subsystem 1 and the B-side air and smoke subsystem 2 can be cooperated with each other, so that under normal conditions, the A-side air and smoke subsystem 1 and the B-side air and smoke subsystem 2 can be operated simultaneously to realize uniform air supply of the A side and the B side of the boiler 100. When low conditions are operated, the A-side air supply assembly 13 is opened and the B-side air supply assembly 23 is closed (or the A-side air supply assembly 13 is closed and the B-side air supply assembly 23 is opened), and meanwhile, the A-side air and smoke subsystem 1 and the B-side air and smoke subsystem 2 are cooperated with each other for adjustment (i.e., the A-side primary air assembly 12, the A-side temporary boiler cold air supply main pipe assembly 16, the B-side primary air assembly 22 and the B-side temporary boiler cold air supply main pipe assembly 26 are adjusted), so that the boiler 100 air volume can be reasonably adjusted through multiple paths, the surge problem of the A-side air supply assembly 13 and the B-side air supply assembly 23 (i.e., the output end valve opening of the corresponding side air supply assembly is too small to cause the surge of the fan) is avoided, the reliability of the deep peak shaving air volume control of the coal-fired power generating unit is improved, the stable operation of the unit equipment under low conditions is ensured, the unit energy consumption is reduced, the unit ammonia injection amount and ammonia escape are reduced, and the environmental protection and economy of the unit are improved.

[0031] Referring to Figures 1 to 6 , the part of the A-side air supply assembly 13 downstream of the A-side intersection point is connected with the atmosphere through the second A-side valve pipe 17; the part of the B-side air supply assembly 23 downstream of the B-side intersection point is connected with the atmosphere through the second B-side valve pipe 27.

[0032] It is not difficult to understand that due to the large air volume of the boiler 100 under hot state, when the oxygen content of the boiler 100 reaches 9-10% or above, the power consumption of the air and smoke system and the exhaust smoke heat loss of the boiler 100 are increased, and due to the high oxygen content of the denitration system, the high-concentration nitrogen oxide after conversion is increased, the ammonia injection amount of the ammonia injection system and the ammonia escape are increased. In the above scheme, when the air supply amount of the unit is surplus, the surplus air volume (i.e., the surplus gas transported from the A-side air supply assembly 13 and the B-side air supply assembly 23) can be directly discharged into the atmosphere through the second A-side valve pipe 17 and the second B-side valve pipe 27, thereby effectively reducing the environmental protection emission oxygen content, saving the ammonia consumption and limestone consumption, and reducing the power consumption of the dust removal system.

[0033] Of course, in another embodiment, the A-side air supply assembly 13 is connected to the A-side furnace cold air supply mother pipe assembly 16 through the second A-side valve pipe 17 downstream of the A-side intersection. Correspondingly, the B-side furnace cold air supply mother pipe assembly 26 can also be connected to the B-side furnace cold air supply mother pipe assembly 26. Further, when the unit air supply is surplus, it can be transferred to the A-side furnace cold air supply mother pipe assembly 16 and the B-side furnace cold air supply mother pipe assembly 26 to store energy, so as to pressurize the A-side furnace cold air supply mother pipe assembly 16 and the B-side furnace cold air supply mother pipe assembly 26 in low working conditions, and further realize peak regulation, such as: surplus gas can be compressed and stored, and used to increase the pressure of the A-side furnace cold air supply mother pipe assembly 16 and the B-side furnace cold air supply mother pipe assembly 26 in low working conditions, so as to supply air to the A-side and B-side of the boiler 100 through the A-side furnace cold air supply mother pipe assembly 16 and the B-side furnace cold air supply mother pipe assembly 260.

[0034] Specifically, the second A-side valve pipe 17 includes an A-side air supply and air exhaust electric valve 171 and an A-side air supply and air exhaust electric regulating valve 172 connected in series with each other; and the second B-side valve pipe 27 includes a B-side air supply and air exhaust electric valve 271 and a B-side air supply and air exhaust electric regulating valve 272 connected in series with each other.

[0035] Specifically, the A-side furnace cold air supply mother pipe assembly 16 includes an A-side furnace cold air supply mother pipe 160, and an A-side furnace electric valve 161 and an A-side furnace electric regulating valve 162 connected in series between the A-side intersection and the A-side furnace cold air supply mother pipe 160; and the B-side furnace cold air supply mother pipe assembly 26 includes a B-side furnace cold air supply mother pipe 260, and a B-side furnace electric valve 261 and a B-side furnace electric regulating valve 262 connected in series between the B-side intersection and the B-side furnace cold air supply mother pipe 260.

[0036] Referring to Figures 1 to 6 , the A-side primary air assembly 12 includes an A-side primary air fan 121, an A-side primary air fan outlet electric valve 122 and an A-side primary air fan outlet electric regulating valve 123; the A-side air supply assembly 13 includes an A-side air supply fan 131 and an A-side air supply fan outlet electric valve 132; one end of the first A-side valve pipe 15 is connected between the A-side primary air fan outlet electric valve 122 and the A-side primary air fan outlet electric regulating valve 123, and the other end is connected downstream of the A-side air supply fan outlet electric valve 132; the B-side primary air assembly 22 includes a B-side primary air fan 221, a B-side primary air fan outlet electric valve 222 and a B-side primary air fan outlet electric regulating valve 223; the B-side air supply assembly 23 includes a B-side air supply fan 231 and a B-side air supply fan outlet electric valve 232; one end of the first B-side valve pipe 25 is connected between the B-side primary air fan outlet electric valve 222 and the B-side primary air fan outlet electric regulating valve 223, and the other end is connected downstream of the B-side air supply fan outlet electric valve 232.

[0037] Specifically, the first A-side valve pipe fitting 15 comprises an A-side primary air supply branch electric valve 151 and an A-side primary air supply branch electric regulating valve 152. Referring to Figures 1 to 6 The air supply communication valve pipe fitting 3 comprises a communication pipe 31 and an air supply communication electric valve 32 arranged on the communication pipe 31.

[0038] Based on the above-mentioned boiler air and flue gas system suitable for deep peak regulation, the application further provides a peak regulation method, comprising the following steps: When the unit is in a condition higher than 35% of the rated condition, the A-side primary air assembly 12, the A-side air supply assembly 13, the A-side flue gas exhaust assembly 14, the B-side primary air assembly 22, the B-side air supply assembly 23, the B-side flue gas exhaust assembly 24 and the air supply communication valve pipe fitting 3 are opened, and the first A-side valve pipe fitting 15, the A-side furnace cold air supply mother pipe assembly 16, the second A-side valve pipe fitting 17, the first B-side valve pipe fitting 25, the B-side furnace cold air supply mother pipe assembly 26 and the second B-side valve pipe fitting 27 are closed.

[0039] That is, referring to Figure 2At this time, in the A-side air and flue gas subsystem 1, the A-side primary air supply branch electric valve 151, the A-side primary air supply branch electric regulating valve 152, the A-side near-burner electric valve 161, the A-side near-burner electric regulating valve 162, the A-side air supply and air discharge electric valve 171 and the A-side air supply and air discharge electric regulating valve 172 are in a closed state, while the A-side primary air fan 121 of the A-side primary air assembly 12 is in a normal operation state, and the A-side primary air fan outlet electric valve 122 and the A-side primary air fan outlet electric regulating valve 123 are in an open state to deliver the primary air to the boiler 100 through the A-side air preheater 11; the A-side air supply fan 131 of the A-side air supply assembly 13 is in a normal operation state, and the A-side air supply fan outlet electric valve 132 is in an open state to deliver the secondary air to the boiler 100 through the A-side air preheater 11; the A-side flue gas discharge assembly 14 is connected with the boiler 100 through the A-side air preheater 11 to realize the flue gas discharge of the boiler 100. Correspondingly, in the B-side air and flue gas subsystem 2, the B-side primary air supply branch electric valve 251, the B-side primary air supply branch electric regulating valve 252, the B-side near-burner electric valve 261, the B-side near-burner electric regulating valve 262, the B-side air supply and air discharge electric valve 271 and the B-side air supply and air discharge electric regulating valve 272 are in a closed state, while the B-side primary air fan 221 of the B-side primary air assembly 22 is in a normal operation state, and the B-side primary air fan outlet electric valve 222 and the B-side primary air fan outlet electric regulating valve 223 are in an open state to deliver the primary air to the boiler 100 through the B-side air preheater 21; the B-side air supply fan 231 of the B-side air supply assembly 23 is in a normal operation state, and the B-side air supply fan outlet electric valve 232 is in an open state to deliver the secondary air to the boiler 100 through the B-side air preheater 21; the B-side flue gas discharge assembly 24 is connected with the boiler 100 through the B-side air preheater 21 to realize the flue gas discharge of the boiler 100.

[0040] Referring to Figure 3 and Figure 4 , the above peak regulation method further comprises the following steps: Under the 20%-35% rated load condition, the A-side air supply assembly 13 is shut down. Specifically, referring to Figure 2 , the A-side air supply fan 131 is shut down, and the A-side air supply fan outlet electric valve 132 is closed.

[0041] The output of the B-side air supply assembly 23 is increased to maintain the minimum air volume requirement under the 20%-35% rated load condition. Specifically, the output of the B-side air supply fan 231 is increased to maintain the minimum air volume requirement under the 20%-35% rated load condition.

[0042] determining whether the B-side air supply assembly 23 has a trip failure, if not, maintaining operation, if yes, closing the B-side air supply assembly 23, and opening the B-side temporary boiler cold air supply main assembly 26, at the same time, opening the first A-side valve pipe 15, and increasing the A-side primary air assembly 12 output to maintain the minimum air volume requirement under 20%-35% rated load working condition. Specifically, referring to Figure 4 opening the B-side temporary boiler electric valve 261 and the B-side temporary boiler electric regulating valve 262, and increasing the B-side temporary boiler cold air supply main 260 pressure, at the same time, ensuring that the A-side primary air fan outlet electric valve 122, the A-side primary air fan outlet electric regulating valve 123, the A-side primary air supply branch electric valve 151, and the A-side primary air supply branch electric regulating valve 152 are opened, and adjusting the air volume from the A-side primary air assembly 12 to the A-side air supply assembly 13 through the A-side primary air fan outlet electric regulating valve 123 and the A-side primary air supply branch electric regulating valve 152.

[0043] In another embodiment (not shown in the figure), the peak shaving method includes the following steps: Under 20%-35% rated load working condition, stopping the B-side air supply assembly 23. Specifically, stopping the B-side air blower 231, and closing the B-side air blower outlet electric valve 232.

[0044] Increasing the A-side air supply assembly 13 output to maintain the minimum air volume requirement under 20%-35% rated load working condition. Specifically, increasing the A-side air blower 131 output to maintain the minimum air volume requirement under 20%-35% rated load working condition.

[0045] determining whether the A-side air supply assembly 13 has a trip failure, if not, maintaining operation, if yes, closing the A-side air supply assembly 13, and opening the A-side temporary boiler cold air supply main assembly 16, at the same time, opening the first B-side valve pipe 25, and increasing the B-side primary air assembly 22 output to maintain the minimum air volume requirement under 20%-35% rated load working condition. Specifically, opening the A-side temporary boiler electric valve 161 and the A-side temporary boiler electric regulating valve 162, and increasing the A-side temporary boiler cold air supply main 160 pressure, at the same time, ensuring that the B-side primary air fan outlet electric valve 222, the B-side primary air fan outlet electric regulating valve 223, the B-side primary air supply branch electric valve 251, and the B-side primary air supply branch electric regulating valve 252 are opened, and adjusting the air volume from the B-side primary air assembly 22 to the B-side air supply assembly 23 through the B-side primary air fan outlet electric regulating valve 223 and the B-side primary air supply branch electric regulating valve 252.

[0046] Referring to Figure 5 In another embodiment, the peak shaving method includes the following steps: At 20%-35% rated load conditions, open A-side air supply to air exhaust electric valve 171, B-side air supply to air exhaust electric valve 271, A-side air supply to air exhaust electric regulating valve 172 and B-side air supply to air exhaust electric regulating valve 272; Synchronously regulate A-side air supply to air exhaust electric regulating valve 172 and B-side air supply to air exhaust electric regulating valve 272 to send part of the air directly into the atmosphere to maintain the minimum required air volume at 20%-35% rated load conditions.

[0047] Referring to Figure 6 In another embodiment, the peak regulation method comprises the following steps: At 20%-35% rated load conditions, open A-side air supply to air exhaust electric valve 171, B-side air supply to air exhaust electric valve 271, A-side air supply to air exhaust electric regulating valve 172 and B-side air supply to air exhaust electric regulating valve 272; Synchronously regulate A-side air supply to air exhaust electric regulating valve 172 and B-side air supply to air exhaust electric regulating valve 272 to send part of the air directly into the atmosphere to maintain the minimum required air volume at 20%-35% rated load conditions.

[0048] It is worth mentioning that, Figures 1 to 6 The dashed line indicates that this branch is disconnected in the current state, i.e. in an inactive state.

[0049] The above embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application. Any non-essential changes and substitutions made by those skilled in the art on the basis of the present application are within the scope of the present application.

Claims

1. A boiler flue gas system suitable for deep peak shaving, used for supplying air to a boiler (100) and exhausting flue gas from a boiler (100), characterized in that, Includes the A-side flue gas subsystem (1), the B-side flue gas subsystem (2), and the air supply connection valves and fittings (3); The A-side flue gas subsystem (1) includes an A-side air preheater (11), and an A-side primary air assembly (12), an A-side air supply assembly (13), and an A-side flue gas assembly (14) connected to the boiler (100) via the A-side air preheater (11); the A-side primary air assembly (12) and the A-side air supply assembly (13) are connected by a first A-side valve fitting (15), and the A-side junction between the first A-side valve fitting (15) and the A-side air supply assembly (13) is also connected to the A-side near-furnace cold air supply main pipe assembly (16); The B-side flue gas subsystem (2) includes a B-side air preheater (21), and a B-side primary air assembly (22), a B-side air supply assembly (23), and a B-side flue gas assembly (24) connected to the boiler (100) via the B-side air preheater (21); the B-side primary air assembly (22) and the B-side air supply assembly (23) are connected by a first B-side valve fitting (25), and the B-side junction between the first B-side valve fitting (25) and the B-side air supply assembly (23) is also connected to the B-side near-furnace cold air supply main pipe assembly (26); The air supply connection valve fitting (3) connects the A-side air supply assembly (13) and the B-side air supply assembly (23).

2. A boiler flue gas system suitable for deep peak shaving according to claim 1, characterized in that, The portion of the A-side air supply assembly (13) located downstream of the A-side junction point is connected to the A-side furnace cold air supply main assembly (16) and / or the atmosphere via the second A-side valve fitting (17); And / or, The portion of the B-side air supply assembly (23) located downstream of the B-side junction point is connected to the B-side furnace cold air supply main assembly (26) and / or the atmosphere via the second B-side valve fitting (27).

3. A boiler flue gas system suitable for deep peak shaving according to claim 2, characterized in that, The second A-side valve fitting (17) includes an A-side air supply to air exhaust electric valve (171) and an A-side air supply to air exhaust electric regulating valve (172) connected in series. And / or, The second B-side valve fitting (27) includes a B-side air supply to air exhaust electric valve (271) and a B-side air supply to air exhaust electric regulating valve (272) connected in series.

4. A boiler flue gas system suitable for deep peak shaving according to claim 2, characterized in that, The A-side furnace cold air supply main pipe assembly (16) includes an A-side furnace cold air supply main pipe (160), and an A-side furnace electric valve (161) and an A-side furnace electric regulating valve (162) connected in series between the A-side junction point and the A-side furnace cold air supply main pipe (160). And / or, The B-side furnace cold air supply main pipe assembly (26) includes the B-side furnace cold air supply main pipe (260), and the B-side furnace electric valve (261) and the B-side furnace electric regulating valve (262) connected in series between the B-side junction point and the B-side furnace cold air supply main pipe (260).

5. A boiler flue gas system suitable for deep peak shaving according to claim 1 or 2, characterized in that, The primary air assembly (12) on side A includes a primary air fan (121) on side A, an electric valve (122) at the outlet of the primary air fan on side A, and an electric regulating valve (123) at the outlet of the primary air fan on side A. The A-side air supply assembly (13) includes an A-side air supply fan (131) and an A-side air supply fan outlet electric valve (132). One end of the first A-side valve fitting (15) is connected between the A-side primary air fan outlet electric valve (122) and the A-side primary air fan outlet electric regulating valve (123), and the other end is connected downstream of the A-side blower outlet electric valve (132). And / or, The primary air assembly (22) on the B side includes a primary air fan (221) on the B side, an electric valve (222) at the outlet of the primary air fan on the B side, and an electric regulating valve (223) at the outlet of the primary air fan on the B side. The B-side air supply assembly (23) includes a B-side air supply fan (231) and a B-side air supply fan outlet electric valve (232). One end of the first B-side valve fitting (25) is connected between the B-side primary air fan outlet electric valve (222) and the B-side primary air fan outlet electric regulating valve (223), and the other end is connected downstream of the B-side blower outlet electric valve (232).

6. A boiler flue gas system suitable for deep peak shaving according to claim 1, characterized in that, The air supply communication valve fitting (3) includes a connecting pipe (31) and an air supply communication electric valve (32) disposed on the connecting pipe (31).

7. A peak-shaving method for a boiler flue gas system suitable for deep peak shaving, based on any one of claims 1-6, characterized in that, Includes the following steps: Under 20%-35% rated load conditions, shut down the A-side air supply component (13). Increase the output of the B-side air supply component (23) to maintain the minimum specified air volume under 20%-35% rated load conditions; Determine whether the B-side air supply assembly (23) has tripped. If not, keep it running. If so, shut down the B-side air supply assembly (23) and open the B-side furnace cold air supply main pipe assembly (26). At the same time, open the first A-side valve fitting (15) to increase the output of the A-side primary air assembly (12) in order to maintain the minimum specified value of air volume under the rated load condition of 20%-35%. or, Under 20%-35% rated load conditions, shut down the B-side air supply component (23). Increase the output of the A-side air supply component (13) to maintain the minimum specified air volume under 20%-35% rated load conditions; Determine whether the A-side air supply component (13) has tripped. If not, continue to operate. If so, shut down the A-side air supply component (13) and open the A-side furnace cold air supply main pipe component (16). At the same time, open the first B-side valve fitting (25) to increase the output of the B-side primary air component (22) in order to maintain the minimum specified value of air volume under the rated load condition of 20%-35%.

8. The peak-shaving method according to claim 7, characterized in that, Includes the following steps: When the unit is operating at 35% above its rated capacity, open the A-side primary air assembly (12), A-side air supply assembly (13), A-side smoke exhaust assembly (14), B-side primary air assembly (22), B-side air supply assembly (23), B-side smoke exhaust assembly (24) and air supply connection valve fitting (3); and close the first A-side valve fitting (15), A-side boiler cold air supply main pipe assembly (16), second A-side valve fitting (17), first B-side valve fitting (25), B-side boiler cold air supply main pipe assembly (26) and second B-side valve fitting (27).

9. A peak-shaving method for a boiler flue gas system suitable for deep peak shaving, based on any one of claims 1-6, characterized in that, Includes the following steps: Under the 20%-35% rated load condition, open the A-side supply air to air exhaust electric valve (171), the B-side supply air to air exhaust electric valve (271), the A-side supply air to air exhaust electric regulating valve (172), and the B-side supply air to air exhaust electric regulating valve (272), and simultaneously regulate the A-side supply air to air exhaust electric regulating valve (172) and the B-side supply air to air exhaust electric regulating valve (272) so that some air is directly supplied to the atmosphere to maintain the minimum specified air volume under the 20%-35% rated load condition.

10. A peak-shaving method for a boiler flue gas system suitable for deep peak shaving, based on any one of claims 1-6, characterized in that, Includes the following steps: Under the 20%-35% rated load condition, open the A-side furnace electric valve (161), the B-side furnace electric valve (261), the A-side furnace electric regulating valve (162), and the B-side furnace electric valve (261), and simultaneously regulate the A-side furnace electric regulating valve (162) and the B-side furnace electric valve (261) so that part of the air volume is connected in series to the A-side furnace cold air supply main pipe (160) and the B-side furnace cold air supply main pipe (260) to maintain the minimum specified air volume under the 20%-35% rated load condition.

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