Bed material energy storage system capable of being coupled with circulating fluidized bed boiler

Abstract

The invention relates to a bed material energy storage method capable of being coupled with a circulating fluidized bed boiler. A cyclone separator, a material returning device and a multi-bin energy storage bubbling bed are included. Wherein the cyclone separator can be a separator in an original unit, the cyclone separator mainly plays a role in gas-solid separation, under the action of centrifugal force, bed materials are rotationally separated to the bottom along the outer wall of the cyclone separator, and flue gas leaves the separator from a center cylinder of the cyclone separator and enters a tail flue of the boiler. And the bed material separated by the cyclone separator enters the material returning device through the vertical pipe. Bed materials in the material returning device enter the multi-branch-bin energy storage bubbling bed, and heating and heat release are achieved on the bed materials through the multi-branch-bin energy storage bubbling bed. The invention mainly aims to provide a bed material energy storage method capable of being coupled with a circulating fluidized bed boiler, so that the huge heat storage capacity of the bed material of the circulating fluidized bed boiler can be fully utilized.

Description

Technical Field

[0001] The invention relates to a circulating fluidized bed boiler, and in particular to a bed material energy storage method that can be coupled with a circulating fluidized bed boiler. Background Art

[0002] With the continuous growth of volatile and intermittent renewable energy generation, the power system needs greater flexibility to ensure the absorption of variable renewable energy. With the advancement of technology, thermal power plants are now required to provide a wider range of peak-to-valley capabilities. For thermal power units that provide high-parameter industrial steam supply, in order to ensure stable industrial steam supply, the upper limit of the unit load is limited, affecting the capacity electricity price and peak-shaving benefits. At the same time, the lower limit of the unit load is limited by the adjustment of environmental protection parameters under low boiler load. The circulating fluidized bed boiler ash circulation system has a huge heat storage capacity, but due to current technical limitations, it has not been able to play a role in peak-to-valley. Summary of the invention

[0003] The main purpose of the present invention is to provide a bed material energy storage method that can be coupled with a circulating fluidized bed boiler, so as to fully utilize the huge heat storage capacity of the bed material of the circulating fluidized bed boiler.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a bed material energy storage method that can be coupled with a circulating fluidized bed boiler. The material separated by the cyclone separator enters the return device. A No. 1 cone valve and a No. 2 cone valve are respectively arranged at both ends of the return device. The No. 1 cone valve is connected to the external bed, and the No. 2 cone valve is connected to the multi-bin energy storage bubbling bed. An industrial steam supply heating surface is arranged in the multi-bin energy storage bubbling bed. The industrial steam supply heating surface can heat the steam of the steam-water system. The steam-water system is connected to the original industrial steam supply pipeline through the energy storage industrial steam supply pipeline: When the unit is under low load or needs deep peak regulation, each compartment of the multi-compartment energy storage bubbling bed is ventilated to enter the bubbling bed state, and the industrial steam supply entering the multi-compartment energy storage bubbling bed maintains the minimum cooling flow. Then, the bed material amount in the multi-compartment energy storage bubbling bed is gradually increased by controlling the No. 2 cone valve. At the same time, the bed material temperature is gradually increased by heating the industrial steam supply heating surface. When the bed material temperature in the multi-compartment energy storage bubbling bed is close to the bed material temperature in the return device, the No. 2 cone valve is closed; then , close the fluidizing dampers of each compartment of the multi-compartment energy storage bubbling bed to stop the fluidization of the bed material of the multi-compartment energy storage bubbling bed. At the same time, continue to maintain the industrial gas supply entering the multi-compartment energy storage bubbling bed at the minimum cooling flow for 20 minutes, and then close the energy storage industrial steam supply pipeline; finally, when a cooling ash shell is formed around the industrial steam supply heating surface in the multi-compartment energy storage bubbling bed, stop the heating of the industrial steam supply heating surface of the multi-compartment energy storage bubbling bed, so that the multi-compartment energy storage bubbling bed enters the energy storage stage; When the unit is in the high load stage, first, the industrial steam supply pipeline entering the multi-compartment energy storage bubbling bed is opened, and then the fluidization dampers of each compartment of the multi-compartment energy storage bubbling bed are ventilated to make the multi-compartment energy storage bubbling bed enter the bubbling bed state; then, the industrial steam supply circuit provided by the unit's exhaust is cut off, and the hot bed material of the multi-compartment energy storage bubbling bed is used to heat the steam generated by the steam-water system to meet the industrial steam supply.

[0005] Preferably, when the unit is in the high load stage, as the temperature of the bed material in the multi-compartment energy storage bubbling bed gradually decreases, the industrial steam supply circuit provided by the unit's exhaust is opened, and the gas production of the multi-compartment energy storage bubbling bed is mixed with the industrial steam supply in the industrial steam supply circuit provided by the unit's exhaust steam to supply steam together; when the temperature of the bed material in the multi-compartment energy storage bubbling bed drops to a preset temperature, the heat release stage ends, and the multi-compartment energy storage bubbling bed re-enters the energy storage stage.

[0006] Further preferably, the steam-water system includes a deaerator water tank, an energy storage water supply pump, an energy storage steam-water separator, an energy storage circulating water pump and an energy storage bottom header. The water in the deaerator water tank is pressurized by the energy storage water supply pump and then replenished into the energy storage steam-water separator. The energy storage steam-water separator circulates the separated water to the energy storage bottom header through the energy storage circulating water pump. The water in the energy storage bottom header is heated by the heating surface in the multi-compartment energy storage bubbling bed to form saturated steam and saturated water to the energy storage steam-water separator.

[0007] The beneficial effects of the present invention are: 1. Improve energy efficiency: When the unit is at low load or needs deep peak regulation, thermal energy is stored in the multi-compartment energy storage bubbling bed. When the unit is at high load, the stored thermal energy is used to heat the steam generated by the steam-water system to meet industrial steam supply needs. This can avoid energy waste and improve overall energy utilization efficiency.

[0008] 2. Enhance the peak load regulation capability of the units: The method of the present invention uses bed material energy storage to enable the unit to more flexibly adjust energy output when the load changes, especially during deep peak regulation, and can provide stable thermal energy support, thereby enhancing the peak regulation capability and operating stability of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0010] Figure 1 It is a flow chart of material circulation of the present invention; Figure 2 Flow chart of the soda system of the present invention.

[0011] Description of Reference Numerals 1. Primary air chamber of circulating fluidized bed boiler; 2. Furnace; 3. Cyclone separator; 4. Standpipe; 5. Return device; 6. Cone valve No. 2; 7. Cone valve No. 1; 8. Feeder return pipe; 11. Ash channel at the entrance of multi-storage energy storage bubbling bed; 12. Industrial steam supply heating surface 1; 13. Industrial steam supply heating surface 2; 14. Industrial steam supply heating surface 3; 101. Deaerator water tank; 102. Energy storage water supply pump; 103. Energy storage steam-water separator; 104. Energy storage circulating water pump; 105. Energy storage bottom header; 106. Multi-storage energy storage bubbling bed wall tube evaporation heating surface; 108. Energy storage primary desuperheater; 110. Energy storage secondary desuperheater; 112. Energy storage industrial steam supply pressure regulating valve; 113. Original industrial steam supply pipeline. DETAILED DESCRIPTION

[0012] The technical scheme in the embodiment of the present invention is described clearly and completely below in conjunction with the accompanying drawings in the embodiment of the present invention. In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0013] like Figure 1 and Figure 2As shown, this embodiment provides a bed material energy storage system that can be coupled with a circulating fluidized bed boiler, including a cyclone separator 3, a recycler 5 and a multi-bin energy storage bubbling bed 10. Among them, the cyclone separator 3 can adopt the separator in the original unit. The cyclone separator 3 mainly plays the role of gas-solid separation. Under the action of centrifugal force, the bed material (and circulating ash, the primary air chamber 1 of the circulating fluidized bed boiler is blown into the furnace 2, the ash in the furnace 2 enters the cyclone separator 3, and the ash is separated by the cyclone separator 3 to form bed material) rotates and separates to the bottom along the outer wall of the cyclone separator 3, and the flue gas leaves the separator from the central tube of the cyclone separator 3 and enters the boiler tail flue. The bed material separated by the cyclone separator 3 enters the recycler 5 through the riser 4. In this embodiment, a No. 1 cone valve 7 and a No. 2 cone valve 6 are respectively arranged at both ends of the returner 5. The No. 1 cone valve 7 is connected to the external bed, and the No. 2 cone valve 6 is connected to the multi-bin energy storage bubbling bed 10 through the inlet ash channel 11 of the multi-bin energy storage bubbling bed 10. Through the returner 5 with double cone valves, the bed material flows smoothly from the cyclone separator 3 to the furnace 2, and at the same time, the flue gas in the furnace 2 will not flow back to the cyclone separator 3. At the same time, the returner 5 with double cone valves can flexibly distribute the amount of bed material entering the external bed and the multi-bin energy storage bubbling bed 10. The amount of bed material entering the external bed is controlled by controlling the opening of the No. 1 cone valve 7, so as to achieve the purpose of controlling the bed temperature and steam temperature. By controlling the No. 2 cone valve 6, that is, controlling the bed material flow entering the multi-bin energy storage bubbling bed 10, that is, controlling the energy storage rate, it is also possible to ensure that the bed temperature in the furnace 2 changes gently without affecting the normal operation of the boiler.

[0014] An industrial steam supply heating surface is arranged in the multi-compartment energy storage bubbling bed 10, and the industrial steam supply heating surface can heat the steam of the steam-water system. The steam-water system is connected to the original industrial steam supply pipeline 113 through the energy storage industrial steam supply pipeline.

[0015] In the heating stage, that is, when the unit is under low load or needs deep peak regulation, each compartment of the multi-compartment energy storage bubbling bed 10 is ventilated to enter the bubbling bed state, and the industrial steam supply entering the multi-compartment energy storage bubbling bed 10 maintains the minimum cooling flow rate. Then, the bed material amount in the multi-compartment energy storage bubbling bed 10 is gradually increased by controlling the No. 2 cone valve 6. At the same time, the bed material temperature is gradually increased by heating the industrial steam supply heating surface. When the bed material temperature in the multi-compartment energy storage bubbling bed 10 is close to the bed material temperature in the return device 5, the No. 2 cone valve 6 is closed; Next, the fluidizing dampers of each bin of the multi-bin energy storage bubbling bed 10 are closed to stop the fluidization of the bed material of the multi-bin energy storage bubbling bed 10. At the same time, the industrial gas supply entering the multi-bin energy storage bubbling bed 10 is maintained at the minimum cooling flow rate for 20 minutes, and then the energy storage industrial steam supply pipeline is closed; finally, when a cooling ash shell is formed around the industrial steam supply heating surface in the multi-bin energy storage bubbling bed 10, the heating of the industrial steam supply heating surface of the multi-bin energy storage bubbling bed 10 is stopped, so that the multi-bin energy storage bubbling bed 10 enters the energy storage stage; In the heat release stage, that is, when the unit is in the high-load stage, first, the energy storage industrial steam supply pipeline entering the multi-storage energy storage bubbling bed 10 is connected, and then the fluidized dampers of each compartment of the multi-storage energy storage bubbling bed 10 are ventilated, so that the multi-storage energy storage bubbling bed 10 enters the bubbling bed state; then, the industrial steam supply circuit provided by the unit exhaust is cut off, and the hot bed material of the multi-storage energy storage bubbling bed 10 is used to heat the steam generated by the steam-water system to meet the industrial steam supply. In addition, when the unit is in the high-load stage, as the temperature of the bed material in the multi-storage energy storage bubbling bed 10 gradually decreases, the industrial steam supply circuit provided by the unit exhaust is opened, and the steam production of the multi-storage energy storage bubbling bed 10 is mixed with the industrial steam supply in the industrial steam supply circuit provided by the unit exhaust to supply steam together. When the bed material temperature in the multi-storage energy storage bubbling bed 10 drops to the preset temperature, the heat release stage ends, and the multi-storage energy storage bubbling bed 10 re-enters the energy storage stage. That is to say, when the demand for industrial steam supply is relatively small, only the multi-bin energy storage bubbling bed 101 can be fluidized, and the industrial steam supply heating surface 12 can be put into operation, and the steam supply temperature can be guaranteed in combination with the energy storage first-stage desuperheater 108. As the bed material temperature in the multi-bin energy storage bubbling bed 101 decreases, when the industrial steam supply temperature demand cannot be met, the multi-bin energy storage bubbling bed 102 is fluidized in turn, and the cooling water of the energy storage second-stage desuperheater 110 is coordinated to control the industrial steam supply temperature to meet the needs of users, that is, the industrial steam supply heating surface 2 13 is put into operation. Similarly, the multi-bin energy storage bubbling bed 103 is put into operation as needed to make the industrial steam supply heating surface 3 14 work. This solution can increase the energy storage time and reduce the fluidization wind energy consumption at the same time. When the heat release stage is over, the energy storage industrial steam supply pressure regulating valve 112 is closed.

[0016] In this embodiment, the steam-water system includes a deaerator water tank 101, an energy storage water supply pump 102, an energy storage steam-water separator 103, an energy storage circulating water pump 104 and an energy storage bottom header 105. The water in the deaerator water tank 101 is pressurized by the energy storage water supply pump 102 and then added to the energy storage steam-water separator 103. The energy storage steam-water separator 103 circulates the separated water to the energy storage bottom header 105 through the energy storage circulating water pump 104. The water in the energy storage bottom header 105 is heated by the evaporation heating surface 106 of the wall-wrapped tube of the multi-bin energy storage bubbling bed 10 to form saturated steam and saturated water to the energy storage steam-water separator 103. Among them, the evaporation heating surface 106 of the wall-wrapped tube constitutes the outer wall structure of the multi-bin energy storage bubbling bed 10, which is sprayed with wear-resistant paint, and the outer wall is wrapped with insulation material and iron shell. The saturated steam separated in the energy storage steam-water separator 103 enters the industrial steam supply heating surface 12 and is heated to superheated steam that meets the requirements of industrial users. When the superheated steam temperature is higher than the user's requirements, the industrial steam supply temperature is controlled by the energy storage primary desuperheater 108. At the same time, the industrial steam supply pressure is controlled by the industrial steam supply pressure regulating valve and the variable frequency energy storage industrial steam supply and water supply pump to meet the requirements of industrial users, and then it is combined with the original industrial steam supply pipeline 113 and supplied to users.

[0017] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A bed material energy storage method capable of being coupled with a circulating fluidized bed boiler, characterized in that: The materials separated by the cyclone separator enter the return device. Cone valve No. 1 and cone valve No. 2 are respectively set at both ends of the return device. Cone valve No. 1 is connected to the external bed, and cone valve No. 2 is connected to the multi-bin energy storage bubbling bed. The multi-bin energy storage bubbling bed is equipped with an industrial steam supply heating surface, which can heat the steam of the steam-water system. The steam-water system is connected to the original industrial steam supply pipeline through the energy storage industrial steam supply pipeline: When the unit is under low load or needs deep peak regulation, each compartment of the multi-compartment energy storage bubbling bed is ventilated to enter the bubbling bed state, and the industrial steam supply entering the multi-compartment energy storage bubbling bed maintains the minimum cooling flow. Then, the bed material amount in the multi-compartment energy storage bubbling bed is gradually increased by controlling the No. 2 cone valve. At the same time, the bed material temperature is gradually increased by heating the industrial steam supply heating surface. When the bed material temperature in the multi-compartment energy storage bubbling bed is close to the bed material temperature in the return device, the No. 2 cone valve is closed; then , close the fluidizing dampers of each compartment of the multi-compartment energy storage bubbling bed to stop the fluidization of the bed material of the multi-compartment energy storage bubbling bed. At the same time, continue to maintain the industrial gas supply entering the multi-compartment energy storage bubbling bed at the minimum cooling flow for 20 minutes, and then close the energy storage industrial steam supply pipeline; finally, when a cooling ash shell is formed around the industrial steam supply heating surface in the multi-compartment energy storage bubbling bed, stop the heating of the industrial steam supply heating surface of the multi-compartment energy storage bubbling bed, so that the multi-compartment energy storage bubbling bed enters the energy storage stage; When the unit is in the high load stage, first, the industrial steam supply pipeline entering the multi-compartment energy storage bubbling bed is opened, and then the fluidization dampers of each compartment of the multi-compartment energy storage bubbling bed are ventilated to make the multi-compartment energy storage bubbling bed enter the bubbling bed state; then, the industrial steam supply circuit provided by the unit's exhaust is cut off, and the hot bed material of the multi-compartment energy storage bubbling bed is used to heat the steam generated by the steam-water system to meet the industrial steam supply.

2. A bed material energy storage method capable of being coupled with a circulating fluidized bed boiler according to claim 1, characterized in that: When the unit is in the high load stage, as the temperature of the bed material in the multi-division energy storage bubbling bed gradually decreases, the industrial steam supply circuit provided by the unit's exhaust is opened, and the gas production of the multi-division energy storage bubbling bed is mixed with the industrial steam supply in the industrial steam supply circuit provided by the unit's exhaust steam to supply steam together. When the bed material temperature in the multi-division energy storage bubbling bed drops to the preset temperature, the heat release stage ends, and the multi-division energy storage bubbling bed re-enters the energy storage stage.

3. A bed material energy storage method capable of being coupled with a circulating fluidized bed boiler according to claim 2, characterized in that: The steam-water system includes a deaerator water tank, an energy storage water supply pump, an energy storage steam-water separator, an energy storage circulating water pump and an energy storage bottom header. The water in the deaerator water tank is pressurized by the energy storage water supply pump and then added to the energy storage steam-water separator. The energy storage steam-water separator circulates the separated water to the energy storage bottom header through the energy storage circulating water pump. The water in the energy storage bottom header is heated by the heating surface in the multi-compartment energy storage bubbling bed to form saturated steam and saturated water to the energy storage steam-water separator.

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