Coal-fired unit primary and secondary air system coupled with compressed air for energy storage

Abstract

The utility model discloses a coal-fired unit primary and secondary air system coupled with compressed air for energy storage, the coal-fired unit comprises a primary flue gas and air system and a secondary flue gas and air system, and the primary flue gas and air system and the secondary flue gas and air system are respectively provided with a primary fan and a secondary fan. A compressed air energy storage power station is coupled in the coal-fired unit, and waste heat generated after compressed air of the compressed air energy storage power station does work is introduced into an outlet bypass of a primary air fan of the coal-fired unit through an air pipe to serve as a bypass air source of primary air. Or a compressed air energy storage power station is coupled in the coal-fired unit, and waste heat generated after the compressed air of the compressed air energy storage power station acts is introduced into an outlet bypass of a secondary fan of the coal-fired unit through an air pipe. The air heater not only replaces the hot air heating function of the air heater, but also can be suitable for a unit with frequent peak regulation as long as a compressed air energy storage power station is put into operation, and air source consumption and coal consumption of the air heater are greatly saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of thermal power generation, and in particular relates to a primary and secondary air system of a coal-fired unit coupled with compressed air energy storage. Background Art

[0002] Energy resource endowment determines that coal-fired power will still be the main source of electricity and power in my country at present and for a long period of time in the future. With the rapid increase in new energy installed capacity and power generation, the utilization hours of coal-fired power units are constantly decreasing. Coal-fired power will take on more peak-shaving tasks and gradually transform from a power source of power to a power source of power and power regulation. Improving the flexibility of coal-fired power units, especially the deep peak-shaving capability, will play a positive role in achieving scientific peak-shaving, ensuring the reliable supply of heating and electricity for people's livelihood, and promoting the development of new energy.

[0003] Due to their inherent defects, the peak load of most coal-fired power units is around 40%. After years of exploration of peak load regulation, the peak load of newly built units is currently around 25%. If it is reduced further, it will affect the safe and stable operation of the units.

[0004] Compressed air energy storage has emerged as a form of energy storage. The compressed air energy storage technology is relatively mature, and its installed capacity, service life, and regulation performance are comparable to those of small and medium-sized pumped storage power stations. With the increase in the scale of single units and the decrease in construction costs, it is gradually approaching the role and benefits of large pumped storage power stations. Compared with pumped storage power stations, it is not restricted by water resources and has the advantages of short construction period, small land occupation, and small environmental impact.

[0005] At present, the power conversion efficiency of compressed air energy storage technology is 50% to 65%, and the utilization efficiency of cold-heat-electricity comprehensive energy is 70% to 80%. The conversion efficiency is still relatively low and the operating cost is high. The comprehensive efficiency of the compressed air energy storage system is closely related to the energy efficiency of each subsystem, and a comprehensive study is required from the aspects of equipment, process, and application scenarios.

[0006] In order to solve the above-mentioned technical problems of peak-shaving of coal-fired units and comprehensive energy efficiency of cooling-heating-electricity of compressed air energy storage, a primary and secondary air system of coal-fired units coupled with compressed air energy storage is proposed. Utility Model Content

[0007] The purpose of the utility model is to provide a primary and secondary air system of a coal-fired unit coupled with compressed air energy storage to solve the problems raised in the above-mentioned background technology.

[0008] The purpose of the utility model is achieved through the following technical solutions: a primary and secondary air system of a coal-fired unit coupled with compressed air energy storage, comprising a coal-fired unit, the coal-fired unit comprising a primary smoke and air system and a secondary smoke and air system, the primary smoke and air system and the secondary smoke and air system are respectively provided with a primary fan and a secondary fan, the coal-fired unit is coupled with a compressed air energy storage power station, and the waste heat of the compressed air of the compressed air energy storage power station after work is introduced into the outlet bypass of the primary fan of the coal-fired unit through an air duct as a bypass wind source for the primary air;

[0009] Or the coal-fired unit is coupled with a compressed air energy storage power station, and the waste heat of the compressed air in the compressed air energy storage power station after work is introduced into the outlet bypass of the secondary fan of the coal-fired unit through the air duct as the bypass wind source of the secondary air.

[0010] Furthermore, the primary air system of the coal-fired unit includes two groups of primary air fan outlet bypasses.

[0011] Furthermore, the compressed air energy storage power station includes a compressor, the outlet end of the compressor is connected to the inlet of the gas storage reservoir, the outlet end of the gas storage reservoir is connected to the turbine through a connecting pipe, and the turbine is connected to the outlet bypass of the primary fan through a connecting pipe.

[0012] Furthermore, control valves are provided on the connecting pipelines between the outlet bypass of the primary fan, the outlet bypass of the secondary fan and the turbine.

[0013] Furthermore, the coal-fired unit also includes an air preheater, and a hot air recirculation duct is arranged in the secondary air duct at the outlet of the air preheater, and the hot air recirculation duct introduces the secondary hot air at the outlet of the air preheater into the secondary air blower.

[0014] Furthermore, the turbine exhaust temperature of the compressed air energy storage power station is 60°C, and the pressure is maintained above the primary wind pressure head, 10-17 kPa;

[0015] When the compressed air energy storage power station is in operation, the control valve installed on the connecting pipeline of the turbine is opened, and the exhaust gas of the turbine passes through the bypass, the primary fan, the air preheater, the coal mill, and then enters the furnace.

[0016] Furthermore, the compressed air energy storage power station connected to the bypass wind source of the primary air and the bypass wind source of the secondary air works intermittently.

[0017] Furthermore, the compressed air energy storage power station has an energy storage time of 8 hours, a power generation time of 4 hours per unit per day, and controls the peak load of the coal-fired units within 5%.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] The utility model adopts a primary air solution for coal-fired units coupled with compressed air energy storage. On the one hand, the compressed air energy storage power station is used for further deep peak regulation of the coal-fired power station. On the other hand, the waste heat of the turbine of the compressed air energy storage power station after work is used as the primary air source of the coal-fired power station.

[0020] Compressed air energy storage, as a means of deep peak regulation, can further reduce the output of generators. Taking a 60MW compressed air energy storage power station (storage time is 8 hours, and the number of generating hours per unit is 4 hours per day) and a conventional 350MW coal-fired unit as an example, the peak load of the coal-fired unit can be reduced to less than 5%, and deep peak regulation of the coal-fired unit can be achieved, or even zero output of the coal-fired unit. Deep peak regulation allows coal-fired units to configure more new energy indicators and share energy storage with new energy companies to obtain benefits.

[0021] The utility model not only replaces the function of the air heater to heat the hot air, but can also be applied as long as the compressed air energy storage power station is put into operation. It is especially suitable for units with frequent peak load regulation, which greatly saves the air source consumption of the air heater and further saves coal consumption.

[0022] The utility model replaces the pressurizing function of the primary fan and the blower, and the turbine exhaust pressure is maintained above the primary and secondary air pressure heads. As long as the compressed air energy storage power station is put into operation, this technology can be applied, especially for units with frequent peak load regulation, which greatly reduces the power consumption of the plant and further saves coal consumption.

[0023] The utility model improves the air temperature at the air preheater inlet, prevents the occurrence of corrosion at the cold end of the air preheater, reduces the resistance of the air preheater, reduces the output of the fan, and reduces the power consumption of the fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the utility model coal-fired unit;

[0025] Figure 2 It is a schematic diagram of coupling the utility model coal-fired unit and the compressed air energy storage power station. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are 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 device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] like Figure 1-2 As shown, a primary and secondary air system of a coal-fired unit coupled with compressed air energy storage comprises a coal-fired unit 1, wherein the coal-fired unit 1 comprises a primary smoke and air system 2 and a secondary smoke and air system 3, wherein the primary smoke and air system 2 and the secondary smoke and air system 3 are respectively provided with a primary fan 4 and a secondary fan 5, wherein a compressed air energy storage power station 6 is coupled to the coal-fired unit 1, and the waste heat of the compressed air of the compressed air energy storage power station 6 after doing work is introduced into the outlet bypass of the primary fan 4 of the coal-fired unit 1 through an air duct as a bypass wind source for the primary air;

[0030] Or the coal-fired unit 1 is coupled with a compressed air energy storage power station, and the waste heat of the compressed air after work in the compressed air energy storage power station is introduced into the outlet bypass of the secondary fan 5 of the coal-fired unit 1 through the air duct as the bypass wind source of the secondary air.

[0031] The primary air system of the coal-fired unit 1 includes two groups of primary air fan outlet bypasses.

[0032] The compressed air energy storage power station 6 includes a compressor 7, the outlet end of the compressor 7 is connected to the inlet of the gas storage reservoir 8, the outlet end of the gas storage reservoir 8 is connected to the turbine 9 through a connecting pipe, and the turbine 9 is connected to the outlet bypass of the primary fan 4 through a connecting pipe.

[0033] In order to facilitate switching of the air intake volume during use, a control valve 10 is provided on the connecting pipeline between the outlet bypass of the primary fan 4 , the outlet bypass of the secondary fan 5 and the turbine 9 .

[0034] The coal-fired unit 1 also includes an air preheater, and a hot air recirculation pipeline is arranged at the secondary air duct at the outlet of the air preheater, and the hot air recirculation pipeline introduces the secondary hot air at the outlet of the air preheater into the secondary air blower (the compressed air energy storage power station 6 of the secondary air system does not work);

[0035] The upper end of the air preheater is connected to the desulfurization reaction tower, and the lower end is connected to the dust collector through a pipeline. The dust collector is connected to the induced draft fan through a pipeline, and the induced draft fan is directly exhausted to the chimney through the pipeline.

[0036] The exhaust temperature of the turbine 9 of the compressed air energy storage power station 6 is 60°C and the pressure is 10-17kPa;

[0037] When the compressed air energy storage power station 6 is in operation, the control valve 10 provided on the connecting pipeline of the turbine 9 is opened, and the exhaust gas of the turbine 9 passes through the bypass, the primary fan, the air preheater, the coal mill, and then enters the furnace.

[0038] When two groups of compressed air energy storage power stations 6 are provided, the compressed air energy storage power stations 6 do not work simultaneously, and the compressed air energy storage power stations 6 connected to the bypass wind sources of the primary air and the bypass wind sources of the secondary air work intermittently.

[0039] The compressed air energy storage power station 6 has an energy storage time of 8 hours, and a power generation time of 4 hours per unit per day, and controls the peak load of the coal-fired unit 1 to be within 5%.

[0040] The compressed air of the compressed air energy storage power station is introduced into the bypass of the primary fan outlet of the coal-fired power station through the air duct after the waste heat after the turbine works. This air is used as the bypass air source of the primary air. When the compressed air energy storage power station is put into operation, the bypass damper is opened, and the exhaust of the turbine passes through the bypass, passes through the primary fan, air preheater, and coal mill, and enters the furnace; when the compressed air energy storage power station is shut down, the bypass damper is closed.

[0041] Compressed air energy storage, as a means of deep peak regulation, can further reduce the output of generators. Taking a 60MW compressed air energy storage power station (storage time is 8 hours, and the number of generating hours per unit is 4 hours per day) and a conventional 350MW coal-fired unit as an example, the peak load of the coal-fired unit can be reduced to less than 5%, and deep peak regulation of the coal-fired unit can be achieved, or even zero output of the coal-fired unit. Deep peak regulation allows coal-fired units to configure more new energy indicators and share energy storage with new energy companies to obtain benefits.

[0042] The exhaust temperature of the turbine is about 60℃ and the pressure is 10-17kPa. After adopting this solution, the exhaust waste heat of the turbine is used as part of the input heat source of the boiler, preventing the exhaust waste heat of the turbine from being discharged into the atmosphere and causing energy waste. Taking the 60MW compressed air energy storage power station and the 350MW unit heater as examples, the coal saving is about 0.9g / kw·h.

[0043] Compared with conventional coal-fired units, the utility model not only replaces the function of the heater to heat the hot air, but also can be applied as long as the compressed air energy storage power station is put into operation, especially for units with frequent peak load regulation, which greatly saves the air source consumption of the heater and further saves coal consumption.

[0044] The air temperature at the air preheater inlet is increased, which prevents the occurrence of corrosion at the cold end of the air preheater, reduces the air preheater resistance, reduces the fan output, and reduces the fan power consumption.

[0045] The technical progress achieved by the utility model is that the technology of the present invention can be applied to coal-fired units of 50MW, 100MW, 300MW, 600MW and 1000MW grades. In the thermal power plant, a group of peak-shaving units can be selected to adopt compressed air energy storage peak-shaving means for peak-shaving, which can provide a large amount of flexible peak-shaving power for the system without increasing the total coal consumption, effectively alleviate the problem of new energy power consumption, release more new energy projects, and further improve the comprehensive energy utilization efficiency of compressed air energy storage cold-heat-electricity.

[0046] The primary and secondary air systems of coal-fired units coupled with compressed air energy storage can not only solve the peak-shaving problem of coal-fired power plants, but also promote the consumption of new energy power generation and improve the comprehensive energy utilization efficiency of compressed air energy storage for cooling, heat and electricity. It is easy to implement and suitable for large-scale promotion and application.

[0047] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A primary and secondary air system of a coal-fired unit coupled with compressed air energy storage, comprising a coal-fired unit (1), characterized in that: The coal-fired unit (1) comprises a primary smoke and air system (2) and a secondary smoke and air system (3), wherein the primary smoke and air system (2) and the secondary smoke and air system (3) are respectively provided with a primary fan (4) and a secondary fan (5), wherein the coal-fired unit (1) is coupled with a compressed air energy storage power station (6), and the waste heat after the compressed air of the compressed air energy storage power station (6) does work is introduced into the outlet bypass of the primary fan (4) of the coal-fired unit (1) through an air duct, and serves as a bypass wind source for the primary air; Alternatively, a compressed air energy storage power station (6) is coupled to the coal-fired unit (1), and waste heat from compressed air in the compressed air energy storage power station (6) after work is introduced into the outlet bypass of the secondary air fan (5) of the coal-fired unit (1) through an air duct to serve as a bypass wind source for the secondary air.

2. The primary and secondary air system of a coal-fired unit coupled with compressed air energy storage according to claim 1 is characterized in that: The primary air system of the coal-fired unit (1) comprises two groups of primary air fan outlet bypasses.

3. The primary and secondary air system of a coal-fired unit coupled with compressed air energy storage according to claim 2 is characterized in that: The compressed air energy storage power station (6) comprises a compressor (7), the outlet end of the compressor (7) is connected to the inlet end of the gas storage reservoir (8), the outlet end of the gas storage reservoir (8) is connected to a turbine (9) via a connecting pipe, and the turbine (9) is connected to the outlet bypass of the primary fan (4) via a connecting pipe.

4. The primary and secondary air system of a coal-fired unit coupled with compressed air energy storage according to claim 3 is characterized in that: A control valve (10) is provided on the connecting pipelines of the outlet bypass of the primary fan (4), the outlet bypass of the secondary fan (5) and the turbine (9).

5. The primary and secondary air system of a coal-fired unit coupled with compressed air energy storage according to claim 4 is characterized in that: The coal-fired unit (1) further comprises an air preheater, wherein a hot air recirculation duct is arranged at the secondary air duct at the outlet of the air preheater, and the hot air recirculation duct introduces the secondary hot air at the outlet of the air preheater into the secondary air blower; The upper end of the air preheater is connected to the desulfurization reaction tower, and the lower end is connected to the dust collector through a pipeline. The dust collector is connected to the induced draft fan through a pipeline, and the induced draft fan is directly exhausted to the chimney through the pipeline.

6. The primary and secondary air system of a coal-fired unit coupled with compressed air energy storage according to claim 5 is characterized in that: The exhaust temperature of the turbine (9) of the compressed air energy storage power station (6) is 60° C. and the pressure is 10-17 kPa; When the compressed air energy storage power station (6) is in operation, the control valve (10) provided on the connection pipeline of the turbine (9) is opened, and the exhaust gas of the turbine (9) passes through the bypass, the primary fan, the air preheater, the coal mill, and then enters the furnace.

7. The primary and secondary air system of a coal-fired unit coupled with compressed air energy storage according to claim 6 is characterized in that: The compressed air energy storage power station (6) connected to the bypass wind source of the primary air and the bypass wind source of the secondary air works intermittently.

8. The primary and secondary air system of a coal-fired unit coupled with compressed air energy storage according to claim 7 is characterized in that: The compressed air energy storage power station (6) has an energy storage time of 8 hours, a power generation time of 4 hours per unit per day, and controls the peak load of the coal-fired unit (1) to be within 5%.

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