Thermal power peak shaving system and method integrating steam ejector and steam thermal storage device

Abstract

The application discloses a thermal power peak shaving system and method integrating a steam ejector and a steam heat storage device, and the system comprises a coal-fired system and a steam heat storage system; when the unit load is reduced, the steam heat storage system extracts main steam and reheated steam from high-pressure and low-pressure steam storage tanks respectively for storage; when the unit load is increased, the steam in the steam storage tank is used as a power steam source of the steam ejector, the steam ejector is used to inject cylinder exhaust steam, the steam heat in the steam storage tank and the waste heat of the cylinder exhaust steam are fully utilized to heat feed water, steam extraction of the steam turbine is reduced, more steam enters the steam turbine to do work, the outlet steam temperature of the primary steam ejector is higher than the steam extraction temperature of the high-pressure cylinder and the medium-pressure cylinder corresponding to the current load, and the outlet steam temperature of the secondary steam ejector is higher than the steam extraction temperature of the low-pressure cylinder corresponding to the current load, so that the feed water pump can deliver more feed water into the coal-fired boiler to generate more steam to enter the steam turbine to do work, and the unit can meet the requirement of the rapid load variation rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coal-fired power generation technology, in particular to a thermal power peak shaving system and method integrating steam ejector and steam heat storage equipment to improve the operation flexibility of thermal power generating units. BACKGROUND

[0002] Under the background of traditional energy crisis, the use of renewable energy, such as solar energy, wind energy, wave energy and tidal energy, is increasing sharply all over the world. However, the power generated by renewable energy is variable and partly unpredictable, and increasing the share of intermittent renewable energy in the power system brings challenges in increasing net load. However, increasing the share of intermittent renewable energy in the power system brings challenges in grid stability and security. Therefore, it is necessary to improve the flexibility of thermal power generating units to improve the variable load rate of the units to respond to the current complex operating environment. Currently, many researchers have proposed that during the low electricity consumption period, the excess electricity is used to heat the lava for heat storage, and during the electricity consumption peak period, the high-temperature lava is used to heat the feed water. However, due to the addition of energy conversion steps, the energy utilization rate of the system is reduced, and therefore, there is still a large space for improvement of the units. SUMMARY

[0003] In order to solve the problems existing in the prior art, the purpose of the present application is to provide a thermal power peak shaving system and method integrating steam ejector and steam heat storage equipment. The unit is additionally provided with a steam storage tank and a steam ejector. The steam storage tank can reduce the steam entering the cylinder, thereby realizing the rapid load reduction of the unit. The steam ejector can fully utilize the steam heat in the steam storage tank and the waste heat of the cylinder exhaust steam, and can greatly improve the load increasing rate of the unit.

[0004] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0005] The utility model discloses a peak shaving system of thermal power of integrated steam ejector and steam heat storage equipment, including coal burning system and steam heat storage system, coal burning system includes coal burning boiler 1, high pressure cylinder 2, medium pressure cylinder 3, low pressure cylinder 4, generator 5, deaerator 6, high pressure heater 7, low pressure heater 8, condenser 9, condensate pump P1, feed water pump P2, first valve V1, second valve V2, third valve V3, tenth valve V10 and twelfth valve V12, and the main steam outlet of coal burning boiler 1 is connected with the inlet of high pressure cylinder 2, and the reheat steam outlet of coal burning boiler 1 is connected with the inlet of medium pressure cylinder 3, and the exhaust outlet of high pressure cylinder 2 is connected with the reheat steam inlet end of coal burning boiler 1, and the steam extraction outlet end of high pressure cylinder 2 is connected with the hot end inlet of high pressure heater 7 through second valve V2, and the exhaust outlet of medium pressure cylinder 3 is connected with the inlet of low pressure cylinder 4, and the steam extraction outlet of medium pressure cylinder 3 is connected with the hot end inlet of high pressure heater 7 through first valve V1, and the steam extraction outlet of medium pressure cylinder 3 is connected with the inlet of deaerator 6, and the outlet of deaerator 6 is connected with the inlet of feed water pump P2, and the outlet of feed water pump P2 is connected with the cold end inlet of high pressure heater 7 through tenth valve V10, and the cold end outlet of high pressure heater 7 is connected with the feed water inlet of coal burning boiler 1, and the steam extraction outlet of low pressure cylinder 4 is connected with the hot end inlet of low pressure heater 8 through third valve V3, and the exhaust outlet of low pressure cylinder 4 is connected with the inlet of condenser 9, and the outlet of condenser 9 is connected with the inlet of condensate pump P1, and the outlet of condensate pump P1 is connected with the cold end inlet of low pressure heater 8 through twelfth valve V12, and the cold end outlet of low pressure heater 8 is connected with the inlet of deaerator 6, and high pressure cylinder 2, medium pressure cylinder 3, low pressure cylinder 4 and generator 5 share a bearing connection.

[0006] The steam storage system comprises a high-pressure steam storage tank 10, a first-stage steam ejector 11, a low-pressure steam storage tank 12, a second-stage steam ejector 13, a high-temperature feed water heat exchanger 14, a low-temperature feed water heat exchanger 15, a fourth valve V4, a fifth valve V5, a sixth valve V6, a seventh valve V7, an eighth valve V8, a ninth valve V9, an eleventh valve V11 and a thirteenth valve V13; a main steam outlet of the coal-fired boiler 1 is connected to an inlet of the high-pressure steam storage tank 10 through the eighth valve V8; an outlet of the high-pressure steam storage tank 10 is connected to a motive steam inlet of the first-stage steam ejector 11 through the sixth valve V6; an exhaust outlet of the high-pressure cylinder 2 is connected to an ejecting steam extraction end of the first-stage steam ejector 11 through the seventh valve V7; an outlet steam of the first-stage steam ejector 11 is connected to a hot end inlet of the high-temperature feed water heat exchanger 14; a reheat steam outlet of the coal-fired boiler 1 is connected to an inlet of the low-pressure steam storage tank 12 through the ninth valve V9; an outlet of the low-pressure steam storage tank 12 is connected to a motive steam inlet of the second-stage steam ejector 13 through the fifth valve V5; an exhaust outlet of the intermediate-pressure cylinder 3 is connected to an ejecting steam extraction end of the second-stage steam ejector 13 through the fourth valve V4; an outlet steam of the second-stage steam ejector 13 is connected to a hot end inlet of the low-temperature feed water heat exchanger 15; an outlet of the feed water pump P2 is connected to a cold end inlet of the high-temperature feed water heat exchanger 14 through the eleventh valve V11; an outlet of the condensate pump P1 is connected to a cold end inlet of the low-temperature feed water heat exchanger 15 through the thirteenth valve V13; a cold end outlet of the high-temperature feed water heat exchanger 14 is connected to a feed water inlet of the coal-fired boiler 1; and a cold end outlet of the low-temperature feed water heat exchanger 15 is connected to an inlet of the deaerator 6.

[0007] In the coal-fired system, a superheated steam flow divider F1 is arranged between a superheated steam outlet of the coal-fired boiler 1 and the high-pressure steam storage tank 10 and the high-pressure cylinder 2; a reheat steam flow divider F2 is arranged between a reheat steam outlet of the coal-fired boiler 1 and the low-pressure steam storage tank 12 and the intermediate-pressure cylinder 3; a high-pressure steam flow divider F3 is arranged between the high-pressure cylinder 2 and the first-stage steam ejector 11 and the coal-fired boiler 1; a low-pressure steam flow divider F4 is arranged between the intermediate-pressure cylinder 3 and the low-pressure cylinder 4 and the second-stage steam ejector 13; a first feed water flow divider F5 is arranged between an outlet of the feed water pump P2 and a cold end inlet of the high-pressure heater 7 and a cold end inlet of the high-temperature feed water heat exchanger 14; a second feed water flow divider F6 is arranged between the condensate pump P1 and a cold end inlet of the low-pressure heater 8 and a cold end inlet of the low-temperature feed water heat exchanger 15; a first feed water flow combiner M1 is arranged between the coal-fired boiler 1 and a cold end outlet of the high-pressure heater 7 and a cold end outlet of the high-temperature feed water heat exchanger 14; and a second feed water flow combiner M2 is arranged between the deaerator 6 and a cold end outlet of the low-pressure heater 8 and a cold end outlet of the low-temperature feed water heat exchanger 15.

[0008] The main steam is selected as the power steam source of the first-stage steam ejector 11, the pressure range of the main steam is 6MPa-25MPa, the temperature range of the main steam is 560℃-600℃, the pressure range of the outlet steam of the first-stage steam ejector 11 is 3-8MPa, the high-pressure cylinder 2 exhaust steam is selected as the injection steam source of the first-stage steam ejector 11, and the waste heat of the high-pressure cylinder 2 exhaust steam is fully utilized, thereby improving the energy utilization rate of the system.

[0009] The reheat steam is selected as the power steam source of the second-stage steam ejector 13, the pressure range of the reheat steam is 2MPa-6MPa, the temperature range of the reheat steam is 560℃-600℃, the pressure range of the outlet steam of the second-stage steam ejector 13 is 0.5MPa-3MPa, the medium-pressure cylinder 3 exhaust steam is selected as the injection steam source of the second-stage steam ejector 13, and the waste heat of the medium-pressure cylinder 3 exhaust steam is fully utilized, thereby improving the energy utilization rate of the system.

[0010] The storage pressure range of the high-pressure steam storage tank 10 is 9-15MPa, and the storage pressure range of the low-pressure steam storage tank 12 is 1MPa-5MPa, so the eighth valve V8 and the ninth valve V9 can be adjusted to make the steam meet the safe working range of the high-pressure steam storage tank 10 and the low-pressure steam storage tank 12.

[0011] When the thermal power unit needs to reduce the load, the eighth valve V8 or the ninth valve V9 can be freely selected to store the main steam or the reheat steam according to the actual situation, so that the thermal power unit can be more quickly reduced.

[0012] The steam ejectors in the steam heat storage system can be single or multiple to be combined, so that the steam heat storage system can be safely and efficiently operated.

[0013] During the unit load increasing process, the high-pressure steam and the low-pressure steam in the high-pressure steam storage tank 10 and the low-pressure steam storage tank 12 can be adjusted by the sixth valve V6 and the fifth valve V5 to make the released steam be in the preset pressure working range.

[0014] The operation method of the integrated steam ejector and steam heat storage equipment thermal power peak shaving system, when the thermal power unit is normally and smoothly operated, the first valve V1, the second valve V2, the third valve V3, the tenth valve V10 and the twelfth valve V12 are opened, the fourth valve V4, the fifth valve V5, the sixth valve V6, the seventh valve V7, the eighth valve V8, the ninth valve V9, the eleventh valve V11 and the thirteenth valve V13 are closed, only the coal-fired system is operated, and the steam heat storage system is not operated.

[0015] When the thermal power unit needs to reduce load operation, the coal-fired system runs, and the steam heat storage system carries out heat absorption operation, the first valve V1, the second valve V2, the third valve V3, the eighth valve V8, the ninth valve V9, the tenth valve V10 and the twelfth valve V12 are opened, the fourth valve V4, the fifth valve V5, the sixth valve V6, the seventh valve V7, the eleventh valve V11 and the thirteenth valve V13 are closed, the reheated steam and the main steam are respectively led out from the coal-fired boiler 1 to enter the low-pressure steam storage tank 12 and the high-pressure steam storage tank 10, so as to reduce the steam entering the intermediate-pressure cylinder 3 and the high-pressure cylinder 2, thereby realizing the rapid load reduction of the thermal power unit.

[0016] When the thermal power unit needs to reduce load operation, the coal-fired system runs, and the steam heat storage system carries out heat absorption operation, the first valve V1, the second valve V2, the third valve V3, the eighth valve V8, the ninth valve V9, the tenth valve V10 and the twelfth valve V12 are opened, the fourth valve V4, the fifth valve V5, the sixth valve V6, the seventh valve V7, the eleventh valve V11 and the thirteenth valve V13 are closed, the reheated steam and the main steam are respectively led out from the coal-fired boiler 1 to enter the low-pressure steam storage tank 12 and the high-pressure steam storage tank 10, so as to reduce the steam entering the intermediate-pressure cylinder 3 and the high-pressure cylinder 2, thereby realizing the rapid load reduction of the thermal power unit.

[0017] Compared with the prior art, the present invention has the following advantages: The present invention adds a steam storage tank and a two-stage steam ejector. When the unit reduces load, the main steam and reheat steam are extracted and stored by the high-pressure steam storage tank 10 and the low-pressure steam storage tank 12 respectively, which quickly reduces the amount of steam entering the turbine and realizes rapid load reduction of the thermal power unit. When the thermal power unit increases load, the steam in the steam storage tank is used as the power steam source of the steam ejector. The steam ejector is used to eject the exhaust steam from the cylinder, which can make full use of the heat of the steam in the steam storage tank and the waste heat of the exhaust steam from the cylinder to heat the feedwater, reduce the steam extraction from the turbine, and allow more steam to enter the turbine to do work. In addition, the outlet steam temperature of the first-stage steam ejector 11 is higher than the extraction steam temperature of the high-pressure cylinder 2 and the intermediate-pressure cylinder 3 corresponding to the current load, and the outlet steam temperature of the second-stage steam ejector 11 is higher than the extraction steam temperature of the low-pressure cylinder 4 corresponding to the current load. Therefore, the feedwater pump P2 can deliver more feedwater into the coal-fired boiler 1 to generate more steam to enter the turbine to do work, thereby significantly improving the load increase rate of the thermal power unit. This invention can improve the flexibility and economy of thermal power units. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a thermal power peak-shaving system integrating a steam ejector and a steam thermal storage device, as described in this invention.

[0019] In the diagram: 1. Coal-fired boiler; 2. High-pressure cylinder; 3. Medium-pressure cylinder; 4. Low-pressure cylinder; 5. Generator; 6. Deaerator; 7. High-pressure heater; 8. Low-pressure heater; 9. Condenser; 10. High-pressure steam storage tank; 11. First-stage steam ejector; 12. Low-pressure steam storage tank; 13. Second-stage steam ejector; 14. High-temperature feedwater heat exchanger; 15. Low-temperature feedwater heat exchanger; P1. Condensate pump; P2. Feedwater pump; V1-V13. Valves; M1. First feedwater merger; M2. Second feedwater merger; F1. Superheated steam distributor; F2. Reheated steam distributor; F3. High-pressure steam distributor; F4. Low-pressure steam distributor; F5. First feedwater distributor; F6. Second feedwater distributor. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 As shown, the present invention relates to a thermal power peak-shaving system and method integrating a steam ejector and a steam thermal storage device, comprising a coal-fired system and a coupled steam thermal storage system, wherein:

[0022] The coal-fired system comprises a coal-fired boiler 1, a high-pressure cylinder 2, a medium-pressure cylinder 3, a low-pressure cylinder 4, a generator 5, a deaerator 6, a high-pressure heater 7, a low-pressure heater 8, a condenser 9, a condensate pump P1, a feed water pump P2, a first valve V1, a second valve V2, a third valve V3, a tenth valve V10 and a twelfth valve V12; a main steam outlet of the coal-fired boiler 1 is connected with an inlet of the high-pressure cylinder 2; a reheat steam outlet of the coal-fired boiler 1 is connected with an inlet of the medium-pressure cylinder 3; an exhaust outlet of the high-pressure cylinder 2 is connected with a reheat steam inlet of the coal-fired boiler 1; an extraction outlet of the high-pressure cylinder 2 is connected with a hot end inlet of the high-pressure heater 7 through the second valve V2; an exhaust outlet of the medium-pressure cylinder 3 is connected with an inlet of the low-pressure cylinder 4; an extraction outlet of the medium-pressure cylinder 3 is connected with the hot end inlet of the high-pressure heater 7 through the first valve V1; an extraction outlet of the medium-pressure cylinder 3 is connected with an inlet of the deaerator 6; an outlet of the deaerator 6 is connected with an inlet of the feed water pump P2; an outlet of the feed water pump P2 is connected with a cold end inlet of the high-pressure heater 7 through the tenth valve V10; a cold end outlet of the high-pressure heater 7 is connected with a feed water inlet of the coal-fired boiler 1; an extraction outlet of the low-pressure cylinder 4 is connected with a hot end inlet of the low-pressure heater 8 through the third valve V3; an exhaust outlet of the low-pressure cylinder 4 is connected with an inlet of the condenser 9; an outlet of the condenser 9 is connected with an inlet of the condensate pump P1; an outlet of the condensate pump P1 is connected with a cold end inlet of the low-pressure heater 8 through the twelfth valve V12; a cold end outlet of the low-pressure heater 8 is connected with the inlet of the deaerator 6; the high-pressure cylinder 2, the medium-pressure cylinder 3, the low-pressure cylinder 4 and the generator 5 share a bearing connection;

[0023] The steam storage system comprises a high-pressure steam storage tank 10, a first-stage steam ejector 11, a low-pressure steam storage tank 12, a second-stage steam ejector 13, a high-temperature feed water heat exchanger 14, a low-temperature feed water heat exchanger 15, a fourth valve V4, a fifth valve V5, a sixth valve V6, a seventh valve V7, an eighth valve V8, a ninth valve V9, an eleventh valve V11 and a thirteenth valve V13; the main steam outlet of the coal-fired boiler 1 is connected to the inlet of the high-pressure steam storage tank 10 through the eighth valve V8; the outlet of the high-pressure steam storage tank 10 is connected to the motive steam inlet of the first-stage steam ejector 11 through the sixth valve V6; the exhaust outlet of the high-pressure cylinder 2 is connected to the steam extraction inlet of the first-stage steam ejector 11 through the seventh valve V7; the outlet steam of the first-stage steam ejector 11 is connected to the hot end inlet of the high-temperature feed water heat exchanger 14; the reheat steam outlet of the coal-fired boiler 1 is connected to the inlet of the low-pressure steam storage tank 12 through the ninth valve V9; the outlet of the low-pressure steam storage tank 12 is connected to the motive steam inlet of the second-stage steam ejector 13 through the fifth valve V5; the exhaust outlet of the intermediate-pressure cylinder 3 is connected to the steam extraction inlet of the second-stage steam ejector 13 through the fourth valve V4; the outlet steam of the second-stage steam ejector 13 is connected to the hot end inlet of the low-temperature feed water heat exchanger 15; the outlet of the feed water pump P2 is connected to the cold end inlet of the high-temperature feed water heat exchanger 14 through the eleventh valve V11; the outlet of the condensate pump P1 is connected to the cold end inlet of the low-temperature feed water heat exchanger 15 through the thirteenth valve V13; the cold end outlet of the high-temperature feed water heat exchanger 14 is connected to the feed water inlet of the coal-fired boiler 1; and the cold end outlet of the low-temperature feed water heat exchanger 15 is connected to the inlet of the deaerator 6.

[0024] In the coal-fired system, a superheated steam flow divider F1 is arranged between the superheated steam outlet of the coal-fired boiler 1 and the high-pressure steam storage tank 10 and the high-pressure cylinder 2; a reheat steam flow divider F2 is arranged between the reheat steam outlet of the coal-fired boiler 1 and the low-pressure steam storage tank 12 and the intermediate-pressure cylinder 3; a high-pressure steam flow divider F3 is arranged between the high-pressure cylinder 2 and the first-stage steam ejector 11 and the coal-fired boiler 1; a low-pressure steam flow divider F4 is arranged between the intermediate-pressure cylinder 3 and the low-pressure cylinder 4 and the second-stage steam ejector 13; a first feed water flow divider F5 is arranged between the outlet of the feed water pump P2 and the cold end inlet of the high-pressure heater 7 and the cold end inlet of the high-temperature feed water heat exchanger 14; a second feed water flow divider F6 is arranged between the condensate pump P1 and the cold end inlet of the low-pressure heater 8 and the cold end inlet of the low-temperature feed water heat exchanger 15; a first feed water flow combiner M1 is arranged between the coal-fired boiler 1 and the cold end outlet of the high-pressure heater 7 and the cold end outlet of the high-temperature feed water heat exchanger 14; and a second feed water flow combiner M2 is arranged between the deaerator 6 and the cold end outlet of the low-pressure heater 8 and the cold end outlet of the low-temperature feed water heat exchanger 15.

[0025] The main steam is selected as the motive steam source of the first-stage steam ejector 11, the pressure range of the main steam is 6MPa-25MPa, the temperature range of the main steam is 560℃-600℃, the pressure range of the outlet steam of the first-stage steam ejector 11 is 3-8MPa, the high-pressure cylinder 2 exhaust steam is selected as the injection steam source of the first-stage steam ejector 11, and the waste heat of the high-pressure cylinder 2 exhaust steam is fully utilized, thereby improving the energy utilization rate of the system.

[0026] The reheat steam is selected as the motive steam source of the second-stage steam ejector 13, the pressure range of the reheat steam is 2MPa-6MPa, the temperature range of the reheat steam is 560℃-600℃, the pressure range of the outlet steam of the second-stage steam ejector 13 is 0.5MPa-3MPa, the medium-pressure cylinder 3 exhaust steam is selected as the injection steam source of the second-stage steam ejector 13, and the waste heat of the medium-pressure cylinder 3 exhaust steam is fully utilized, thereby improving the energy utilization rate of the system.

[0027] The storage pressure range of the high-pressure steam storage tank 10 is 9-15MPa, and the storage pressure range of the low-pressure steam storage tank 12 is 1MPa-5MPa, so the eighth valve V8 and the ninth valve V9 can be adjusted to make the steam meet the safe working range of the high-pressure steam storage tank 10 and the low-pressure steam storage tank 12.

[0028] When the thermal power unit needs to be load-reduced, the eighth valve V8 or the ninth valve V9 can be freely selected to store the main steam or the reheat steam according to the actual situation, so that the thermal power unit can be load-reduced more quickly.

[0029] The steam ejectors in the steam heat storage system can be single or multiple to make the steam heat storage system run safely and efficiently.

[0030] During the load-increasing process of the unit, the high-pressure steam and the low-pressure steam in the high-pressure steam storage tank 10 and the low-pressure steam storage tank 12 can be adjusted by the sixth valve V6 and the fifth valve V5 to make the released steam be in the appropriate pressure working range.

[0031] When the thermal power unit runs normally and stably, the first valve V1, the second valve V2, the third valve V3, the tenth valve V10 and the twelfth valve V12 are opened, the fourth valve V4, the fifth valve V5, the sixth valve V6, the seventh valve V7, the eighth valve V8, the ninth valve V9, the eleventh valve V11 and the thirteenth valve V13 are closed, only the coal-fired system is run, and the steam heat storage system is not run.

[0032] When the thermal power unit needs to operate at a reduced load, the coal-fired system is operated and the steam heat storage system is operated in heat absorption, the first valve V1, the second valve V2, the third valve V3, the eighth valve V8, the ninth valve V9, the tenth valve V10 and the twelfth valve V12 are opened, the fourth valve V4, the fifth valve V5, the sixth valve V6, the seventh valve V7, the eleventh valve V11 and the thirteenth valve V13 are closed, and the reheated steam and the main steam are led out from the coal-fired boiler 1 to enter the low-pressure steam storage tank 12 and the high-pressure steam storage tank 10, so as to reduce the steam entering the intermediate-pressure cylinder 3 and the high-pressure cylinder 2, thereby realizing rapid load reduction of the thermal power unit;

[0033] When the thermal power unit needs to operate at a reduced load, the coal-fired system is operated and the steam heat storage system is operated in heat absorption, the first valve V1, the second valve V2, the third valve V3, the eighth valve V8, the ninth valve V9, the tenth valve V10 and the twelfth valve V12 are opened, the fourth valve V4, the fifth valve V5, the sixth valve V6, the seventh valve V7, the eleventh valve V11 and the thirteenth valve V13 are closed, and the reheated steam and the main steam are led out from the coal-fired boiler 1 to enter the low-pressure steam storage tank 12 and the high-pressure steam storage tank 10, so as to reduce the steam entering the intermediate-pressure cylinder 3 and the high-pressure cylinder 2, thereby realizing rapid load reduction of the thermal power unit; When the thermal power unit needs to operate at a reduced load, the coal-fired system is operated and the steam heat storage system is operated in heat absorption, the first valve V1, the second valve V2, the third valve V3, the eighth valve V8, the ninth valve V9, the tenth valve V10 and the twelfth valve V12 are opened, the fourth valve V4, the fifth valve V5, the sixth valve V6, the seventh valve V7, the eleventh valve V11 and the thirteenth valve V13 are closed, and the reheated steam and the main steam are led out from the coal-fired boiler 1 to enter the low-pressure steam storage tank 12 and the high-pressure steam storage tank 10, so as to reduce the steam entering the intermediate-pressure cylinder 3 and the high-pressure cylinder 2, thereby realizing rapid load reduction of the thermal power unit;

Claims

1. A thermal power peak shaving system integrating a steam ejector and a steam thermal storage device, characterized in that, The coal-fired system and the steam storage system are connected in series. The coal-fired system comprises a coal-fired boiler (1), a high-pressure cylinder (2), a medium-pressure cylinder (3), a low-pressure cylinder (4), a generator (5), a deaerator (6), a high-pressure heater (7), a low-pressure heater (8), a condenser (9), a condensate pump (P1), a feed water pump (P2), a first valve (V1), a second valve (V2), a third valve (V3), a tenth valve (V10) and a twelfth valve (V12); the main steam outlet of the coal-fired boiler (1) is connected with the inlet of the high-pressure cylinder (2); the reheat steam outlet of the coal-fired boiler (1) is connected with the inlet of the medium-pressure cylinder (3); the exhaust outlet of the high-pressure cylinder (2) is connected with the reheat steam inlet of the coal-fired boiler (1); the steam extraction outlet of the high-pressure cylinder (2) is connected with the hot end inlet of the high-pressure heater (7) through the second valve (V2); the exhaust outlet of the medium-pressure cylinder (3) is connected with the inlet of the low-pressure cylinder (4); the steam extraction outlet of the medium-pressure cylinder (3) is connected with the hot end inlet of the high-pressure heater (7) through the first valve (V1); the steam extraction outlet of the medium-pressure cylinder (3) is connected with the inlet of the deaerator (6); the outlet of the deaerator (6) is connected with the inlet of the feed water pump (P2); the outlet of the feed water pump (P2) is connected with the cold end inlet of the high-pressure heater (7) through the tenth valve (V10); the cold end outlet of the high-pressure heater (7) is connected with the feed water inlet of the coal-fired boiler (1); the steam extraction outlet of the low-pressure cylinder (4) is connected with the hot end inlet of the low-pressure heater (8) through the third valve (V3); the exhaust outlet of the low-pressure cylinder (4) is connected with the inlet of the condenser (9); the outlet of the condenser (9) is connected with the inlet of the condensate pump (P1); the outlet of the condensate pump (P1) is connected with the cold end inlet of the low-pressure heater (8) through the twelfth valve (V12); the cold end outlet of the low-pressure heater (8) is connected with the inlet of the deaerator (6); the high-pressure cylinder (2), the medium-pressure cylinder (3), the low-pressure cylinder (4) and the generator (5) share a bearing connection. The steam storage system comprises a high-pressure steam storage tank (10), a first-stage steam ejector (11), a low-pressure steam storage tank (12), a second-stage steam ejector (13), a high-temperature feed water heat exchanger (14), a low-temperature feed water heat exchanger (15), a fourth valve (V4), a fifth valve (V5), a sixth valve (V6), a seventh valve (V7), an eighth valve (V8), a ninth valve (V9), an eleventh valve (V11) and a thirteenth valve (V13); a main steam outlet of a coal-fired boiler (1) is connected to an inlet of the high-pressure steam storage tank (10) through the eighth valve (V8); an outlet of the high-pressure steam storage tank (10) is connected to a motive steam inlet of the first-stage steam ejector (11) through the sixth valve (V6); an exhaust outlet of a high-pressure cylinder (2) is connected to an injection steam extraction end of the first-stage steam ejector (11) through the seventh valve (V7); an outlet steam of the first-stage steam ejector (11) is connected to a hot end inlet of the high-temperature feed water heat exchanger (14); a reheat steam outlet of the coal-fired boiler (1) is connected to an inlet of the low-pressure steam storage tank (12) through the ninth valve (V9); an outlet of the low-pressure steam storage tank (12) is connected to a motive steam inlet of the second-stage steam ejector (13) through the fifth valve (V5); an exhaust outlet of a medium-pressure cylinder (3) is connected to an injection steam extraction end of the second-stage steam ejector (13) through the fourth valve (V4); an outlet steam of the second-stage steam ejector (13) is connected to a hot end inlet of the low-temperature feed water heat exchanger (15); an outlet of a feed water pump (P2) is connected to a cold end inlet of the high-temperature feed water heat exchanger (14) through the eleventh valve (V11); an outlet of a condensate pump (P1) is connected to a cold end inlet of the low-temperature feed water heat exchanger (15) through the thirteenth valve (V13); a cold end outlet of the high-temperature feed water heat exchanger (14) is connected to a feed water inlet of the coal-fired boiler (1); and a cold end outlet of the low-temperature feed water heat exchanger (15) is connected to an inlet of a deaerator (6).

2. The integrated steam ejector and steam thermal storage apparatus' thermal power peak shaving system according to claim 1, characterized in that, The superheated steam flow divider (F1) is arranged between the superheated steam outlet end of the coal-fired boiler (1) and the high-pressure storage tank (10) and the high-pressure cylinder (2); the reheated steam flow divider (F2) is arranged between the reheated steam outlet end of the coal-fired boiler (1) and the low-pressure storage tank (12) and the medium-pressure cylinder (3); the high-pressure steam flow divider (F3) is arranged between the high-pressure cylinder (2) and the first-stage steam ejector (11) and the coal-fired boiler (1); the low-pressure steam flow divider (F4) is arranged between the medium-pressure cylinder (3) and the low-pressure cylinder (4) and the second-stage steam ejector (13); the first feed water flow divider (F5) is arranged between the outlet of the feed water pump (P2) and the cold end inlet of the high-pressure heater (7) and the cold end inlet of the high-temperature feed water heat exchanger (14); the second feed water flow divider (F6) is arranged between the outlet of the condensate pump (P1) and the cold end inlet of the low-pressure heater (8) and the cold end inlet of the low-temperature feed water heat exchanger (15); the first feed water flow combiner (M1) is arranged between the coal-fired boiler (1) and the cold end outlet of the high-pressure heater (7) and the cold end outlet of the high-temperature feed water heat exchanger (14); and the second feed water flow combiner (M2) is arranged between the deaerator (6) and the cold end outlet of the low-pressure heater (8) and the cold end outlet of the low-temperature feed water heat exchanger (15).

3. The integrated steam ejector and steam thermal storage apparatus for peak shaving of thermal power system according to claim 1, wherein, The main steam is selected as the power steam source of the first-stage steam ejector (11), the pressure range of the main steam is 6MPa-25MPa, the temperature range of the main steam is 560-600℃, the pressure range of the outlet steam of the first-stage steam ejector (11) is 3-8MPa, and the exhaust steam of the high-pressure cylinder (2) is selected as the injection extraction steam source of the first-stage steam ejector (11), so that the waste heat of the exhaust steam of the high-pressure cylinder (2) is fully utilized, and the energy utilization rate of the system is improved.

4. The integrated steam ejector and steam thermal storage apparatus for peak shaving of thermal power system according to claim 1, wherein, The reheated steam is selected as the power steam source of the second-stage steam ejector (13), the pressure range of the reheated steam is 2MPa-6MPa, the temperature range of the reheated steam is 560-600℃, the pressure range of the outlet steam of the second-stage steam ejector (13) is 0.5MPa-3MPa, and the exhaust steam of the medium-pressure cylinder (3) is selected as the injection extraction steam source of the second-stage steam ejector (13), so that the waste heat of the exhaust steam of the medium-pressure cylinder (3) is fully utilized, and the energy utilization rate of the system is improved.

5. The integrated steam ejector and steam thermal storage apparatus for peak shaving of thermal power system according to claim 1, wherein, The storage pressure range of the high-pressure storage tank (10) is 9-15MPa, and the storage pressure range of the low-pressure storage tank (12) is 1MPa-5MPa, so the eighth valve (V8) and the ninth valve (V9) are adjusted respectively to make the steam meet the safe working range of the high-pressure storage tank (10) and the low-pressure storage tank (12).

6. The integrated steam ejector and steam thermal storage apparatus for peak shaving of thermal power system according to claim 1, wherein, When the thermal power unit needs to reduce the load, according to the actual situation, the eighth valve (V8) or the ninth valve (V9) is freely selected to store the main steam or the reheated steam, so that the thermal power unit can reduce the load more quickly.

7. The integrated steam ejector and steam thermal storage apparatus for peak shaving of thermal power system according to claim 1, wherein, The steam ejectors in the steam heat storage system are selected to be single or multiple to be combined, so that the steam heat storage system can be safely and efficiently operated.

8. The integrated steam ejector and steam thermal storage apparatus for peak shaving of thermal power system according to claim 1, wherein, During the process of unit load increase, the high pressure steam in the high pressure steam storage tank (10) and the low pressure steam in the low pressure steam storage tank (12) respectively pass through the sixth valve (V6) and the fifth valve (V5) to adjust the steam pressure, so that the released steam is in the preset pressure working range.

9. The method of operating an integrated steam ejector and steam thermal storage plant for peak shaving of a thermal power plant according to any one of claims 1 to 8, characterized in that, When the thermal power unit is normally and smoothly running, the first valve (V1), the second valve (V2), the third valve (V3), the tenth valve (V10) and the twelfth valve (V12) are opened, and the fourth valve (V4), the fifth valve (V5), the sixth valve (V6), the seventh valve (V7), the eighth valve (V8), the ninth valve (V9), the eleventh valve (V11) and the thirteenth valve (V13) are closed, only the coal-fired system is running, and the steam heat storage system is not running. When the thermal power unit needs to run in load reduction, the coal-fired system runs, and the steam heat storage system runs in heat absorption, the first valve (V1), the second valve (V2), the third valve (V3), the eighth valve (V8), the ninth valve (V9), the tenth valve (V10) and the twelfth valve (V12) are opened, and the fourth valve (V4), the fifth valve (V5), the sixth valve (V6), the seventh valve (V7), the eleventh valve (V11) and the thirteenth valve (V13) are closed, the reheated steam and the main steam are respectively led out from the coal-fired boiler (1) to enter the low pressure steam storage tank (12) and the high pressure steam storage tank (10), so as to reduce the steam entering the steam turbine, thereby realizing the rapid load reduction of the thermal power unit. When the thermal power unit needs to increase load, the coal combustion system is running, and the steam heat storage system is running, the fourth valve (V4), the fifth valve (V5), the sixth valve (V6), the seventh valve (V7), the eleventh valve (V11) and the thirteenth valve (V13) are opened, the first valve (V1), the second valve (V2), the third valve (V3), the eighth valve (V8), the ninth valve (V9), the tenth valve (V10) and the twelfth valve (V12) are closed, the high-pressure steam in the high-pressure steam storage tank (10) is released into the power steam inlet end of the primary steam ejector (11), the exhaust steam of the high-pressure cylinder (2) is introduced into the injection steam extraction end of the primary steam ejector (11), the outlet steam of the primary steam ejector (11) is introduced into the high-temperature feed water heater (14) to heat the feed water, and the steam extraction of the high-pressure cylinder (2) and the medium-pressure cylinder (3) can be reduced; the low-pressure steam in the low-pressure steam storage tank (12) is released into the power steam inlet end of the secondary steam ejector (13), the exhaust steam of the medium-pressure cylinder (3) is introduced into the injection steam extraction end of the secondary steam ejector (13), and the outlet steam of the secondary steam ejector (13) is introduced into the low-temperature feed water heater (15) to heat the condensed water output by the condensed water pump (P1), so that the steam extraction of the medium-pressure cylinder (3) can be reduced, more steam can enter the steam turbine to do work, the outlet steam temperature of the primary steam ejector (11) is higher than the steam extraction temperature of the high-pressure cylinder (2) and the medium-pressure cylinder (3) corresponding to the current load, and the outlet steam temperature of the secondary steam ejector (13) is higher than the steam extraction temperature of the low-pressure cylinder (4) corresponding to the current load, so that the feed water pump (P2) can deliver more feed water into the coal-fired boiler (1) to generate more steam into the steam turbine to do work, thereby realizing the rapid load increase of the thermal power unit.

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