阅读说明：本技术 一种空气-蒸汽联合循环发电系统和方法 (Air-steam combined cycle power generation system and method ) 是由 马勇 杜文斌 韩爽 于 2021-09-17 设计创作，主要内容包括：本发明公开了一种空气-蒸汽联合循环发电系统和方法,包括空气循环发电系统和蒸汽循环发电系统；所述的空气循环发电系统包括同轴连接的空气透平、空气预热器、低压压气机、高压压气机和空气透平带动的发电机；所述的蒸汽循环发电系统包括给水泵、凝汽器、蒸汽透平和蒸汽透平带动的发电机；所述的空气循环发电方法包括步骤一；所述的蒸汽循环发电方法包括步骤二。本发明一方面在传统火电厂蒸汽循环发电系统基础上叠加空气循环发电系统,并实现了压气机耗功转化为热量后在给水系统中的再吸收,这样可以有效提高火电厂经济性；另外一方面,利用空气热容小,升温迅速,可以把传统大机组火电厂改造为小型火力发电厂,提高传统火电厂在人烟稀少等北方极寒地区的负荷匹配性及灵活性。(The invention discloses an air-steam combined cycle power generation system and a method, comprising an air cycle power generation system and a steam cycle power generation system; the air circulation power generation system comprises an air turbine, an air preheater, a low-pressure compressor, a high-pressure compressor and a generator driven by the air turbine which are coaxially connected; the steam cycle power generation system comprises a feed water pump, a condenser, a steam turbine and a generator driven by the steam turbine; the air circulation power generation method comprises the steps of I; the steam cycle power generation method comprises a second step. On one hand, the air circulation power generation system is superposed on the traditional steam circulation power generation system of the thermal power plant, and the reabsorption of the compressor in the water supply system after the power consumption is converted into heat is realized, so that the economical efficiency of the thermal power plant can be effectively improved; on the other hand, the heat capacity of air is small, the temperature rise is rapid, the traditional large-unit thermal power plant can be transformed into a small-sized thermal power plant, and the load matching performance and flexibility of the traditional thermal power plant in extremely cold northern areas with rare people and the like are improved.)

1. An air-steam combined cycle power generation system is characterized by comprising an air cycle power generation system and a steam cycle power generation system;

the air circulation power generation system comprises an air filter inlet pipeline (L1), an air inlet is arranged on the air filter inlet pipeline (L1), an air outlet of the air filter inlet pipeline is connected to an inlet of an air filter (1), an outlet of the air filter (1) is connected to an inlet of a low-pressure compressor (3) through a low-pressure compressor inlet pipeline (L2), an outlet of the low-pressure compressor (3) is connected to an air inlet of an air inter-stage cooler (6) through a compressor inter-stage cooler inlet pipeline (L3), the air outlet of the air inter-stage cooler (6) is connected to an inlet of a high-pressure compressor (4) through a high-pressure compressor inlet pipeline (L6), an outlet of the high-pressure compressor (4) is connected to an inlet of an air preheater (13) arranged in a hearth of a boiler (7) through a high-pressure compressor outlet pipeline (L7), the outlet of the air preheater (13) is connected to the inlet of the air turbine (5) through an air turbine inlet pipeline (L8), a shaft (S1) of a generator driven by the air turbine drives a low-pressure compressor (3), a high-pressure compressor (4) and a generator (2) driven by the air turbine to rotate, do work and generate electricity, the outlet of the air turbine (5) is discharged into a hearth of a boiler (7) through an air turbine exhaust pipeline (L9) to fully recover waste heat and is mixed and combusted with pulverized coal fed into the boiler (7) by a coal mill (8) through a coal mill powder feeding pipeline (L10), and therefore an open type electricity generating cycle of air is completed;

the steam cycle power generation system comprises a feed water pump (9), the outlet of the feed water pump (9) is connected to the inlet of a steam generator (14) arranged in the low temperature region in the boiler (7) through a feed water pump-to-steam generator feed water pipe (L11), the outlet of the steam generator (14) is connected to the inlet of a steam turbine (11) through a steam generator-to-steam turbine main steam pipe (L12), a shaft (S2) of the generator driven by the steam turbine drives the generator (12) driven by the steam turbine to generate electricity, an outlet of the steam turbine (11) is connected to an inlet of a condenser (10) through a steam turbine exhaust pipeline (L13), an outlet of the condenser (10) is connected to a water inlet of a compressor interstage cooler (6) through a compressor interstage cooler water side inlet pipeline (L4), and a water outlet of the compressor interstage cooler (6) is connected to an inlet of a water feed pump (9) through a compressor interstage cooler water side outlet pipeline (L5).

2. An air-steam combined cycle power generation system according to claim 1, wherein the air preheater (13) is a tube preheater capable of withstanding the air pressure at the outlet of the high pressure compressor (4) on the tube side.

3. An air-steam combined cycle power generation system according to claim 1, wherein the temperature of the high pressure air at the tube side of the air preheater (13) has a corresponding upper limit alarm value and main fuel trip value to prevent the air preheater (13) from being burned out due to excessive temperatures.

4. An air-steam combined cycle power generation system according to claim 1, characterized in that the air discharged from the low pressure compressor (3) is fully cooled in the compressor intercooler (6) and then enters the high pressure compressor (4) through the high pressure compressor inlet duct (L6), so that the power consumption of the high pressure compressor (4) can be fully reduced, and the absolute value of the power generation of the air turbine driven generator (2) is increased.

5. An air-steam combined cycle power generation system according to claim 1, wherein the condensed water in the condenser (10) is introduced into the compressor intercooler (6) through a compressor intercooler water-side inlet pipe (L4), and the water having absorbed heat is introduced into the inlet of the feed pump (9) through a compressor intercooler water-side outlet pipe (L5).

6. An air-steam combined cycle power generation method, comprising:

air enters an air filter (1) through an air filter inlet pipeline (L1) to fully filter impurities, then enters a low-pressure compressor (3) through a low-pressure compressor inlet pipeline (L2) to be fully compressed, the compressed air enters a compressor interstage cooler (6) through a low-pressure compressor outlet to a compressor interstage cooler inlet pipeline (L3), after being cooled in the compressor interstage cooler (6), the air enters a high-pressure compressor (4) through a high-pressure compressor inlet pipeline (L6) to be continuously compressed, the further compressed air enters an air preheater (13) arranged in a high-temperature region in a hearth of a boiler (7) through a high-pressure compressor outlet pipeline (L7) to be subjected to heat absorption and temperature rise, and after the air temperature rises to the inlet temperature requirement of a turbine (5), the air enters the air turbine (5) through the air preheater to an air turbine inlet pipeline (L8) to be expanded to do work, the shaft (S1) of the generator is driven by the air turbine to drive the low-pressure air compressor (3), the high-pressure air compressor (4) and the generator (2) driven by the air turbine to do work and generate electricity, finally, the exhaust of the air turbine (5) is discharged into a hearth of the boiler (7) through an air turbine exhaust pipeline (L9) to fully recover waste heat and is mixed with coal powder sent into the boiler (7) by a coal mill (8) through a coal mill powder sending pipeline (L10) for combustion, and thus an open type power generation cycle of air is completed;

a water pump (9) pumps feed water into a steam generator (14) arranged in a low-temperature area in a hearth of the boiler (7) through a feed water pump-to-steam generator feed water pipeline (L11) to absorb heat and evaporate the feed water into superheated steam, enters a steam turbine (11) through a steam generator to steam turbine main steam pipeline (L12) to perform expansion work, the shaft (S2) of the generator is driven by the steam turbine to drive the generator (12) driven by the steam turbine to generate electricity, the steam after expansion work is discharged into a condenser (10) through a steam turbine exhaust pipeline (L13) to be condensed, after water obtained by condensing steam into water in the condenser (10) enters the compressor interstage cooler (6) through a water side inlet pipeline (L4) of the compressor interstage cooler to absorb heat, enters a feed pump (9) through a water side outlet pipeline (L5) of the compressor interstage cooler to continuously complete a closed power generation cycle of steam.

7. An air-steam combined cycle power generation method according to claim 6, characterized in that the air preheater (13) is a tube preheater capable of withstanding the air pressure at the outlet of the high pressure compressor (4) on the tube side.

8. An air-steam combined cycle power generation method according to claim 6, characterized in that the temperature of the high pressure air at the tube side in the air preheater (13) has a corresponding upper limit alarm value and main fuel trip value to prevent the air preheater (13) from being burned out due to overhigh temperature.

Technical Field

The invention belongs to the technical field of power generation equipment, and particularly relates to an air-steam combined cycle power generation system and method.

Background

Currently, research on air-steam combined cycle power generation is relatively few, but research on air as a circulating medium mainly focuses on the research on energy storage and energy release of a power generation system by taking air as an energy storage medium. For example, in chinese patent No. CN112983566, granted on 2021, 06 and 18, the grant date discloses an energy release subsystem and an energy release method applied to a compressed air energy storage system, the system adopts an air turbine to expand and apply work to air with lower pressure, and the air which has applied the work is directly discharged into the environment, so that the waste heat in the environment is increased, and the improvement of the environment is not facilitated. In addition, as the granted date is 2021, 06 and 22 days, and the granted publication number is CN109944650, a combined cooling, heating and power generation system and method containing supercritical compressed air energy storage are disclosed, wherein although both the air turbine 1 and the air turbine 2 participate in power generation, the heat absorbed by the hot air at the inlet of the air turbine is a solar heat collection/storage system, and the air is not heated by the conventional fuel of a thermal power plant. The invention of generating power in a thermal power plant by using an air-steam combined cycle to improve the cycle thermal efficiency and recovering the exhaust gas of an air turbine into a boiler hearth to participate in combustion is also provided for the first time in the invention.

In summary, there is no universal, convenient and reliable power generation scheme for the power generation in thermal power plants by using the air-steam combined cycle power generation system and method.

Disclosure of Invention

The invention aims to provide an air-steam combined cycle power generation system and method which are strong in applicability, convenient and reliable, can miniaturize the conventional thermal power plant and can be used for generating power in the thermal power plant.

The invention is realized by adopting the following technical scheme:

an air-steam combined cycle power generation system comprises an air cycle power generation system and a steam cycle power generation system;

the air circulation power generation system comprises an air filter inlet pipeline, an air inlet is arranged on the air filter inlet pipeline, an air outlet of the air filter inlet pipeline is connected to an inlet of the air filter, an outlet of the air filter is connected to an inlet of a low-pressure compressor through a low-pressure compressor inlet pipeline, an outlet of the low-pressure compressor is connected to an air inlet of an air compressor interstage cooler through a compressor interstage cooler inlet pipeline, an air outlet of the air compressor interstage cooler is connected to an inlet of a high-pressure compressor through a high-pressure compressor inlet pipeline, an outlet of the high-pressure compressor is connected to an inlet of an air preheater arranged in a high-temperature area in a boiler hearth through a high-pressure compressor outlet pipeline, an outlet of the air preheater is connected to an inlet of an air turbine through an air turbine inlet pipeline, a shaft of a generator is driven by the air turbine to drive the low-pressure compressor, a shaft of the generator is driven by the air turbine, The high-pressure compressor and the generator driven by the air turbine rotate to do work and generate electricity, the outlet of the air turbine is discharged into a boiler hearth through an air turbine exhaust pipeline to fully recover waste heat and is mixed with pulverized coal fed into the boiler through a pulverized coal feeding pipeline of a coal mill to combust with the pulverized coal, and thus an open type power generation cycle of air is completed;

the steam cycle power generation system comprises a water feeding pump, an outlet of the water feeding pump is connected to an inlet of a steam generator arranged in a low-temperature area in a boiler hearth through a water feeding pipeline from the water feeding pump to the steam generator, an outlet of the steam generator is connected to an inlet of a steam turbine through a main steam pipeline from the steam generator to the steam turbine, a shaft of a generator is driven by the steam turbine to drive the generator driven by the steam turbine to generate power, an outlet of the steam turbine is connected to an inlet of a condenser through a steam turbine exhaust pipeline, an outlet of the condenser is connected to a water inlet of a compressor interstage cooler through a water side inlet pipeline of the compressor interstage cooler, and a water outlet of the compressor interstage cooler is connected to an inlet of the water feeding pump through a water side outlet pipeline of the compressor cooler.

The invention is further improved in that the air preheater is a tube preheater of which the tube side can bear the air pressure of the outlet of the high-pressure compressor.

In a further improvement of the invention, the temperature of the high pressure air at the tube side of the air preheater has a corresponding upper limit alarm value and a main fuel trip value to prevent the air preheater from being burnt out due to overhigh temperature.

The invention has the further improvement that the air discharged by the low-pressure air compressor is fully cooled in the inter-stage cooler of the air compressor and then enters the high-pressure air compressor through the inlet pipeline of the high-pressure air compressor, so that the power consumption of the high-pressure air compressor can be fully reduced, and the absolute value of the power generation of the generator driven by the air turbine is improved.

The invention is further improved in that the condensed water in the condenser is introduced into the compressor intercooler through a water side inlet pipeline of the compressor intercooler, and the water absorbing heat is introduced into an inlet of the feed pump through a water side outlet pipeline of the compressor intercooler.

An air-steam combined cycle power generation method comprising:

air enters the air filter through an air filter inlet pipeline to fully filter impurities, then enters the low-pressure compressor through a low-pressure compressor inlet pipeline to be fully compressed, the compressed air enters the compressor interstage cooler through a low-pressure compressor outlet to a compressor interstage cooler inlet pipeline, after being cooled in the compressor interstage cooler, the air enters the high-pressure compressor through a high-pressure compressor inlet pipeline to be continuously compressed, the obtained further compressed air enters an air preheater arranged in a high-temperature area in a boiler hearth through a high-pressure compressor outlet pipeline to absorb heat and raise temperature, when the air temperature is raised to the inlet temperature requirement of the air turbine, the air enters the air turbine through the air preheater to an air turbine inlet pipeline to be expanded and do work, and a shaft of the generator is driven by the air turbine to drive the low-pressure compressor, the high-pressure compressor and the generator driven by the air turbine to rotate to do work and generate electricity, finally, the exhaust of the air turbine is discharged into a boiler hearth through an air turbine exhaust pipeline to fully recover waste heat and is mixed with pulverized coal fed into the boiler through a pulverized coal feeding pipeline of a coal mill for combustion, so that an open type power generation cycle of air is completed;

the water pump drives feed water into a steam generator arranged in a low-temperature area in a boiler hearth through a feed water pump and a steam generator feed water pipeline to absorb heat and evaporate the heat into superheated steam, the superheated steam enters a steam turbine through the steam generator and a steam turbine main steam pipeline to perform expansion work, a shaft of a generator is driven by the steam turbine to drive the generator driven by the steam turbine to generate electricity, the steam after the expansion work is discharged into a condenser through a steam turbine exhaust pipeline to be condensed, water after the steam is condensed into water in the condenser enters a compressor interstage cooler through a compressor interstage cooler water side inlet pipeline to absorb heat, and then enters the feed water pump through a compressor interstage cooler water side outlet pipeline to continuously complete a closed electricity generation cycle of the steam.

The invention is further improved in that the air preheater is a tube preheater of which the tube side can bear the air pressure of the outlet of the high-pressure compressor.

In a further improvement of the invention, the temperature of the high pressure air at the tube side of the air preheater has a corresponding upper limit alarm value and a main fuel trip value to prevent the air preheater from being burnt out due to overhigh temperature.

The invention has at least the following beneficial technical effects:

the invention provides an air-steam combined cycle power generation system and method, which superpose an air cycle power generation system on the basis of a traditional steam cycle power generation system, realize the gradient utilization of pulverized coal combustion energy in a boiler and improve the economy of cycle power generation of a thermal power plant. The air discharged by the low-pressure compressor is fully cooled in the compressor interstage cooler and then enters the high-pressure compressor through the high-pressure compressor inlet pipeline, so that the power consumption of the high-pressure compressor can be fully reduced, the absolute value of power generation of a generator driven by an air turbine is improved, in addition, condensed water in the condenser is introduced into the compressor interstage cooler through the compressor interstage cooler water side inlet pipeline, and water absorbing heat is introduced into the water feeding pump inlet through the compressor interstage cooler water side outlet pipeline, so that the average heat absorption temperature of the steam cycle power generation system can be fully improved, and the cycle heat efficiency of the steam cycle power generation system is improved. The invention can fully utilize the characteristics that the air heat capacity is small, and the heat can be absorbed quickly to be heated to a higher temperature, so that the power of a power plant can be reduced to a smaller value, and finally the air-steam combined cycle power generation system can be arranged by a single coal mill, thereby improving the load response flexibility of a thermal power plant.

The system can be arranged in extremely cold areas in the north of China, and the characteristic that the power consumption of the air compressor is greatly reduced when the environmental temperature is low is fully utilized, so that the absolute value of the power generation of the generator (2) driven by the air turbine is greatly improved.

In addition, as the local extremely cold area in the north of China has longer winter time and lower environmental temperature which can be below minus 30 ℃ at the lowest, the breadth of workers is large and the population is relatively rare, the requirement of social development on the load of a power plant is generally lower, but the requirement on heat supply is generally higher, the characteristic that the power generation power of the thermal power plant can be greatly reduced by the air-steam combined cycle power generation system can be fully utilized, and a high back pressure device for directly heating circulating water is arranged in the exhaust steam of a steam turbine (11) in the air-steam combined cycle power generation system, so that the improvement of the method for generating power and supplying heat with high back pressure by the air-steam combined cycle power generation is realized.

In conclusion, after the power consumption of the compressor is converted into the internal energy of the air, the condensed water of the condenser is utilized to absorb heat in the inter-stage cooler of the compressor, so that the power consumption of the compressor is recycled, and the thermodynamic cycle economy is improved.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Description of reference numerals:

1. air filter, 2, air turbine driven generator, 3, low pressure compressor, 4, high pressure compressor, 5, air turbine, 6, compressor interstage cooler, 7, boiler, 8, coal mill, 9, feed water pump, 10, condenser, 11, steam turbine, 12, steam turbine driven generator, 13, air preheater, 14, steam generator, L1, air filter inlet pipe, L2, low pressure compressor inlet pipe, L3, low pressure compressor outlet to compressor interstage cooler inlet pipe, L4, compressor interstage cooler water side inlet pipe, L5, compressor interstage cooler water side outlet pipe, L6, high pressure compressor inlet pipe, L7, high pressure compressor outlet pipe, L8, air preheater to air turbine inlet pipe, L9, air turbine exhaust pipe, L10, coal mill coal feed pipe, l11, feed water pump to steam generator feed water line, L12, steam generator to steam turbine main steam line, L13, steam turbine exhaust line, S1, air turbine driven generator shaft, S2, steam turbine driven generator shaft.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1, the present invention provides an air-steam combined cycle power generation system, which includes an air cycle power generation system and a steam cycle power generation system.

The air circulation power generation system comprises: air enters the air filter 1 through an air filter inlet pipeline L1 to fully filter impurities, then enters the low-pressure compressor 3 through a low-pressure compressor inlet pipeline L2 to be fully compressed, and the compressed air enters the compressor interstage cooler 6 from a low-pressure compressor outlet to a compressor interstage cooler inlet pipeline L3. After being cooled in the compressor interstage cooler 6, the air enters the high-pressure compressor 4 through a high-pressure compressor inlet pipeline L6 to be continuously compressed, and the further compressed air enters an air preheater 13 arranged in a high-temperature area in a hearth of the boiler 7 through a high-pressure compressor outlet pipeline L7 to absorb heat and raise temperature. When the temperature of the air rises to the requirement of the inlet temperature of the air turbine 5, the air enters the air turbine 5 through an air preheater and an air turbine inlet pipeline L8 to do work through expansion, and a shaft S1 of a generator is driven by the air turbine to drive the low-pressure compressor 3, the high-pressure compressor 4 and the generator 2 driven by the air turbine to do work and generate electricity. Finally, the exhaust gas of the air turbine 5 is discharged into a hearth of the boiler 7 through an air turbine exhaust pipeline L9 to fully recover waste heat and is mixed and combusted with the pulverized coal discharged into the boiler 7 from the coal mill 8 through a coal mill powder feeding pipeline L10, so that an open power generation cycle of air is completed.

The steam cycle power generation system includes: the water feeding pump 9 pumps feed water into a steam generator 14 arranged in a low-temperature area in a hearth of the boiler 7 through a water feeding pump-steam generator water feeding pipeline L11 to absorb heat and evaporate the feed water into superheated steam, the superheated steam enters the steam turbine 11 through a steam generator-steam turbine main steam pipeline L12 to do expansion work, and a shaft S2 of the generator is driven by the steam turbine to drive the generator 12 driven by the steam turbine to generate electricity. The steam after expansion work is discharged into the condenser 10 through a steam turbine exhaust pipeline L13 for condensation. After the steam in the condenser 10 is condensed into water, the water enters the compressor intercooler 6 through the water side inlet pipeline L4 of the compressor intercooler to absorb heat, and then enters the feed pump 9 through the water side outlet pipeline L5 of the compressor intercooler to complete a closed power generation cycle of the steam.

The invention provides an air-steam combined cycle power generation method, which comprises the following steps:

the method comprises the following steps: air enters the air filter 1 through an air filter inlet pipeline L1 to fully filter impurities, then enters the low-pressure compressor 3 through a low-pressure compressor inlet pipeline L2 to be fully compressed, and the compressed air enters the compressor interstage cooler 6 from a low-pressure compressor outlet to a compressor interstage cooler inlet pipeline L3. After being cooled in the compressor interstage cooler 6, the air enters the high-pressure compressor 4 through a high-pressure compressor inlet pipeline L6 to be continuously compressed, and the further compressed air enters an air preheater 13 arranged in a high-temperature area in a hearth of the boiler 7 through a high-pressure compressor outlet pipeline L7 to absorb heat and raise temperature. When the temperature of the air rises to the requirement of the inlet temperature of the air turbine 5, the air enters the air turbine 5 through an air preheater and an air turbine inlet pipeline L8 to do work through expansion, and a shaft S1 of a generator is driven by the air turbine to drive the low-pressure compressor 3, the high-pressure compressor 4 and the generator 2 driven by the air turbine to do work and generate electricity. Finally, the exhaust gas of the air turbine 5 is discharged into a hearth of the boiler 7 through an air turbine exhaust pipeline L9 to fully recover waste heat and is mixed and combusted with the pulverized coal discharged into the boiler 7 from the coal mill 8 through a coal mill powder feeding pipeline L10, so that an open power generation cycle of air is completed.

Step two: the water feeding pump 9 pumps feed water into a steam generator 14 arranged in a low-temperature area in a hearth of the boiler 7 through a water feeding pump-steam generator water feeding pipeline L11 to absorb heat and evaporate the feed water into superheated steam, the superheated steam enters the steam turbine 11 through a steam generator-steam turbine main steam pipeline L12 to do expansion work, and a shaft S2 of the generator is driven by the steam turbine to drive the generator 12 driven by the steam turbine to generate electricity. The steam after expansion work is discharged into the condenser 10 through a steam turbine exhaust pipeline L13 for condensation. After the steam in the condenser 10 is condensed into water, the water enters the compressor intercooler 6 through the water side inlet pipeline L4 of the compressor intercooler to absorb heat, and then enters the feed pump 9 through the water side outlet pipeline L5 of the compressor intercooler to continuously complete a closed power generation cycle of the steam.

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.