阅读说明：本技术 一种采用补水箱的燃煤机组灵活性调节系统及调节方法 (coal-fired unit flexibility adjusting system and adjusting method adopting water replenishing tank ) 是由 冯浩波 李�根 严俊杰 陈伟雄 邢秦安 种道彤 于 2019-10-25 设计创作，主要内容包括：一种采用补水箱的燃煤机组灵活性调节系统及调节方法,系统在升负荷时,减小第一给水泵开度,给水量减小,所需汽轮机抽汽变少,汽轮机做功增加；同时,凝汽器液位上升,冷补水箱可以蓄冷凝水防止凝汽器液位过高；给水量减少导致除氧器液位下降,此时热补水箱在第二给水泵驱动下给除氧器补水；系统在降负荷时,高压缸排汽一部分进入喷射式热泵,进入低压缸蒸汽量减少,汽轮机做功减少,喷射式热泵利用汽轮机排汽加热冷补水箱内低温水,并将混合后的高温水注入热补水箱；本发明在原有回热系统基础上增加外部补水箱调节系统,实现机组快速升降负荷的同时,增加了机组蓄热能力,设备结构简单,提高了机组灵活性以及经济性。(A flexibility adjusting system and method for coal-fired unit using water-supplementing tank, the system reduces the water-feeding pump opening degree when increasing load, the water-feeding quantity is reduced, the required steam extraction of turbine is reduced, the work of turbine is increased, at the same time, the liquid level of condenser is raised, the cold-supplementing tank can store cold condensate water to prevent the liquid level of condenser from being too high, the water-feeding quantity is reduced to cause the liquid level of deaerator to drop, at this moment, the hot-supplementing tank supplies water to deaerator under the drive of second water-feeding pump, when reducing load, part of high-pressure cylinder exhaust enters into jet heat pump, the steam amount of low-pressure cylinder is reduced, the work of turbine is reduced, the jet heat pump heats the low-temperature water in the cold-supplementing tank by using the steam extraction of turbine, and injects the mixed high-temperature water into the hot-supplementing tank.)

The flexibility adjusting system is characterized in that a heat supplementing water tank (1) and a cold supplementing water tank (2) are used for adjusting water supplementing and storing heat, and the flexibility adjusting system is quick in response when load is changed, and comprises a boiler (14), a high-pressure cylinder (10), a low-pressure cylinder (11), a deaerator (13), a condenser (12), an injection heat pump (3), the heat supplementing water tank (1), the cold supplementing water tank (2), a high-pressure heat exchanger (16) and a low-pressure heat exchanger (17), wherein the boiler (14) is connected with an inlet of the high-pressure cylinder (10), a steam extraction port of the high-pressure cylinder (10) is connected with a steam extraction inlet of the corresponding high-pressure heat exchanger (16), a steam extraction port of the high-pressure cylinder (10) is connected with an inlet of each stage of the low-pressure cylinder (11), a steam extraction port of the low-pressure cylinder (11) is connected with a steam extraction inlet of the corresponding low-pressure heat exchanger (17), a steam extraction port of the low-pressure cylinder (11) is connected with an inlet of the deaerator (12), a water tank (12), a water supply outlet of the low-pressure cylinder (12) is connected with a water tank (3), a steam injection throttle valve (3), a steam extraction port of the high-supply water tank (13) is connected with a steam-pressure heat exchanger (13), a steam-injection heat exchanger (13), a steam-injection heat exchanger (13) is connected with a secondary steam-injection heat exchanger (13), a secondary steam-injection heat exchanger (13) is connected with a secondary steam-injection heat exchanger (13) inlet of a secondary steam-injection heat exchanger (13), a secondary steam-injection heat exchanger (13) is arranged in a secondary steam-injection heat exchanger (13) between an inlet of the high-injection heat exchanger (3), a steam-injection heat exchanger (13) is arranged in the high-7) is connected with a steam-7) between a steam-7) and a steam-7, a steam-7.

2. The coal-fired unit flexibility adjusting system adopting water replenishing tanks is characterized in that a cold water replenishing tank (2) and a hot water replenishing tank (1) are adopted, the cold water replenishing tank (2) is connected with a condenser (12), the liquid level of the condenser (12) is adjusted by using the cold water replenishing tank (2), the hot water replenishing tank (1) is connected with a deaerator (13), and the hot water replenishing tank (1) is used for replenishing water for the deaerator (13).

3. The kind of flexibility adjustment system of coal-fired unit adopting water replenishing tank as claimed in claim 1, wherein when decreasing load, part of the exhaust steam of the high pressure cylinder (10) enters the jet heat pump (3), the rest exhaust steam enters the low pressure cylinder (11), which results in the decrease of the steam intake of the low pressure cylinder (11), the work of the steam entering the low pressure cylinder (11) is decreased, the coal-fired unit realizes the rapid load decreasing action, the high temperature and high pressure exhaust steam of the high pressure cylinder (10) enters the jet heat pump (3) and then heats the low temperature water in the cold replenishing water tank (2), and drives the mixed high temperature water to enter the hot replenishing water tank (1).

4. The flexibility adjusting system of coal-fired unit adopting water replenishing tank as claimed in claim 1, characterized in that during load increase, the water feeding pump (4) opening is reduced, water feeding amount is reduced, the total amount of heat exchange required when passing through the low-pressure heat exchanger (17) is reduced, heat comes from steam extraction of each stage of low-pressure cylinder, the steam extraction amount of the required low-pressure cylinder (11) is reduced, more steam enters the condenser (12) after doing work, the low-pressure cylinder (11) does work and increases, the unit realizes rapid load increase action, more steam enters the condenser (12) and causes the liquid level of the condenser (12) to rise, the cold water replenishing tank (2) connected with the side port of the hot well of the condenser (12) condenses water to prevent the liquid level of the condenser (12) from being too high, the water feeding amount reduces the liquid level of the deaerator (13), at this time, the hot water replenishing tank (1) supplies water to the deaerator (13) under the drive of the second water feeding pump (8), and maintains the normal.

5. The flexibility adjusting system of kinds of coal-fired units adopting water replenishing tanks, as claimed in claim 1, is characterized in that an injection heat pump (3) is adopted, times of inlets (3-1) of the injection heat pump (3) are used for discharging steam of a high pressure cylinder (10), a secondary inlet (3-2) is used for low temperature water in the cold replenishing water tank (2), and the steam discharged by the high pressure cylinder (10) is used for heating and driving the low temperature water, and finally enters the hot replenishing water tank (1).

6. The adjusting method of the flexibility adjusting system of the coal-fired unit adopting the water replenishing tank as claimed in any of claims 1 to 5 is characterized in that when the system is rapidly increased in load, the throttle valve (5) is opened, the second throttle valve (6), the third throttle valve (7) and the steam valve (9) are closed, the second water feed pump (8) starts to work, the opening degree of the water feed pump (4) is reduced, the main water supply quantity of the outlet of the condenser (12) is reduced, the heat required by the low-pressure heat exchanger (17) is reduced, the heat extraction quantity of each stage of the low-pressure cylinder (11) is reduced, more steam is applied to the condenser (12), more work is applied to the low-pressure cylinder (11), the liquid level of the condenser (12) is increased, the throttle valve (5) of is opened, the liquid level of the cold water replenishing tank (2) is adjusted, the liquid level of the condenser (12) is adjusted to enter the cold water replenishing tank (2), the main water supply quantity is reduced, the liquid level of the deaerator (13) is reduced, the second deaerator (8) drives the high-temperature water in the water tank (1) to enter the cold water replenishing tank (13), the water replenishing tank is maintained, the external heat storage unit.

When the system rapidly reduces the load, the second throttle valve (6), the third throttle valve (7) and the steam valve (9) are opened, the th throttle valve (5) is closed, the th water feed pump (4) is fully opened, the second water feed pump (8) is closed, because the steam valve (9) is opened, part of the steam discharged by the high-pressure cylinder (10) enters the -time inlet (3-1) of the jet heat pump (3), the amount of the steam entering the low-pressure cylinder (11) is reduced, the work of the low-pressure cylinder (11) is reduced, the low-temperature water in the cold water replenishing water tank (2) enters the secondary inlet (3-2) of the jet heat pump (3), the jet heat pump (3) utilizes the high-temperature high-pressure steam discharged by the high-pressure cylinder (10) to heat the low-temperature water in the cold water replenishing water tank (2), and the mixed high-temperature water is injected into the hot water replenishing water tank (1), and the excess heat and the excess.

Technical Field

The invention relates to the technical field of flexibility adjustment of coal-fired units, in particular to a flexibility adjustment system and method for coal-fired units adopting water replenishing tanks.

Background

With the rapid development of economy in China and the increasing improvement of the living standard of people, the power utilization requirement is also continuously improved. The capacity of a coal burner assembling machine in an electric power system is large, and in order to match with new energy power generation grid connection of large-scale wind power, solar energy and the like and change of electricity utilization structures in China, a coal-fired unit can bear more and more difficult peak regulation tasks. This puts higher demands on the flexibility of the coal-fired unit, requires that it can operate with a large amplitude of variable load and has a fast variable load rate. When the power grid requires rapid load change, the heat storage capacity in the system is limited, a more potential heat storage system needs to be matched with a traditional coal-fired unit, the liquid levels of a condenser and a deaerator can change, the vacuum degree is reduced and the supercooling degree is increased due to too high water level of the condenser, the unit economy is affected, and a condensate pump generates cavitation due to too low water level; the oxygen-eliminating device water level is too high and can lead to working medium and thermal loss, and operating pressure is unstable in the oxygen-eliminating device, influences equipment safety and deoxidization effect, and the water level is crossed lowly and can be made the feed pump produce the cavitation. It is necessary to secure the equipment by means of an additional control system or an external device,

disclosure of Invention

In order to overcome the problems in the prior art, the invention aims to provide coal-fired unit flexibility adjusting systems and adjusting methods adopting water replenishing tanks.

In order to achieve the purpose, the invention adopts the technical scheme that:

A flexibility adjusting system of a coal-fired unit adopting a water supplementing tank utilizes a hot water supplementing tank 1 and a cold water supplementing tank 2 to adjust water supplementing and heat storage, and fast response is realized when load is changed, the system comprises a boiler 14, a high-pressure cylinder 10, a low-pressure cylinder 11, a deaerator 13, a condenser 12, an injection type heat pump 3, a hot water supplementing tank 1, a cold water supplementing tank 2, a high-pressure heat exchanger 16 and a low-pressure heat exchanger 17, wherein the boiler 14 is connected with an inlet of the high-pressure cylinder 10, each stage of steam extraction ports of the high-pressure cylinder 10 are respectively connected with a steam extraction inlet of the corresponding high-pressure heat exchanger 16, each stage of steam extraction ports of the high-pressure cylinder 10 are respectively connected with a steam extraction inlet of the corresponding low-pressure heat exchanger 17, each stage of the low-pressure cylinder 11 is respectively connected with a steam extraction inlet of the corresponding low-pressure heat exchanger 17, a steam extraction port of the low-pressure heat exchanger 11 is connected with an inlet of the condenser 12, a water supply inlet of the low-pressure heat exchanger 17 is connected in series, an outlet of the low-pressure heat exchanger 13 is connected with a water supply inlet of the deaerator 13, an outlet of the deaerator 13 is connected with a feed water inlet of the high-16, an injection type heat pump 13, an outlet of the high-3 is connected with a secondary steam injection type heat pump, a secondary steam injection type heat pump 3, a secondary steam injection throttle valve is arranged between a secondary steam injection type steam injection throttle valve 3, a secondary throttle valve 3 and a secondary throttle valve 3 is arranged between a secondary throttle valve 3-3, a secondary throttle valve 3 is arranged in the high-3, a 367 steam injection type steam injection.

A cold water replenishing tank 2 and a hot water replenishing tank 1 are adopted; the cold water replenishing tank 2 is connected with the condenser 12, and the liquid level of the condenser 12 is adjusted by using the cold water replenishing tank 2; the hot water replenishing tank 1 is connected with the deaerator 13, and water is replenished to the deaerator 13 by utilizing the hot water replenishing tank 1;

when the load is reduced, part of the exhaust steam of the high-pressure cylinder 10 enters the jet type heat pump 3, the rest of the exhaust steam enters the low-pressure cylinder 11, the steam inlet amount of the low-pressure cylinder 11 is reduced, the steam enters the low-pressure cylinder 11 to do work, the unit realizes the rapid load reduction action, the exhaust steam of the high-pressure cylinder 10 enters the jet type heat pump 3 and then heats the low-temperature water in the cold water replenishing water tank 2, and the mixed high-temperature water is driven to enter the hot water replenishing water tank 1.

When the load is increased, the opening degree of the th water feeding pump 4 is reduced, the water feeding amount is reduced, the heat required by the temperature increase of the feed water when the feed water passes through the low-pressure heat exchanger 17 is reduced, and the heat comes from the steam extraction of each stage of low-pressure cylinder, so that the steam extraction amount of the low-pressure cylinder 11 is reduced, more steam enters the condenser 12 after doing work, the low-pressure cylinder 11 does work and is increased, the unit realizes the rapid load increasing action, more steam enters the condenser 12 to cause the liquid level of the condenser 12 to rise, cold storage condensate water of the cold water replenishing tank 2 connected with the side port of the hot well of the condenser 12 prevents the liquid level of the condenser 12 from being overhigh, the liquid level of the deaerator 13 is reduced due to the reduction of the water feeding amount, and at the moment.

The jet type heat pump 3 is adopted, a secondary inlet 3-1 of the jet type heat pump 3 is a high-pressure cylinder 10 for steam exhaust, a secondary inlet 3-2 is low-temperature water in the cold water replenishing water tank 2, and the high-pressure cylinder 10 for steam exhaust and heating drives the low-temperature water to finally enter the hot water replenishing water tank 1.

When the system is rapidly loaded, the throttle valve 5 is opened, the second throttle valve 6, the third throttle valve 7 and the steam valve 9 are closed, the second water feed pump 8 starts to work, the opening of the water feed pump 4 is reduced, the main water supply quantity of the outlet of the condenser 12 is reduced, the heat required by the low-pressure heat exchanger 17 is reduced, the backheating steam extraction quantity of each stage of the low-pressure cylinder 11 is reduced, more steam does work and enters the condenser 12, the low-pressure cylinder 11 does more work, the liquid level of the condenser 12 rises, as the throttle valve 5 is opened, the cold water tank 2 adjusts the liquid level of the condenser 12, condensed water enters the cold water tank 2 for storing, the main water supply quantity is reduced, the liquid level of the deaerator 13 is reduced, the second water feed pump 8 drives high-temperature water in the hot water feed tank 1 to enter the deaerator 13, the deaerator 13 liquid level is maintained to be stable, water is supplemented to the system while external heat storage to the coal-fired unit, and the load-up action is rapidly completed by adjusting the external water-.

When the system rapidly reduces the load, the second throttle valve 6, the third throttle valve 7 and the steam valve 9 are opened, the th throttle valve 5 is closed, the th water feed pump 4 is fully opened, the second water feed pump 8 is closed, because the steam valve 9 is opened, part of steam discharged by the high-pressure cylinder 10 enters the -time inlet 3-1 of the jet type heat pump 3, the steam amount entering the low-pressure cylinder 11 is reduced, the work done by the low-pressure cylinder 11 is reduced, low-temperature water in the cold water replenishing water tank 2 enters the secondary inlet 3-2 of the jet type heat pump 3, the jet type heat pump 3 heats the low-temperature water in the cold water replenishing water tank 2 by using the high-temperature high-pressure steam discharged by the high-pressure cylinder 10, and injects the mixed high-temperature water into the hot water replenishing water tank 1, and achieves rapid load reduction of the unit.

Compared with the prior art, the invention has the following advantages:

1) according to the invention, when the water supply tank adjusting system is used for increasing the load, the opening degree of the th water supply pump 4 is reduced, the water supply amount is reduced, the heat required by the temperature increase of the feed water when the feed water passes through the low-pressure heat exchanger 17 is reduced, the heat comes from the steam extraction of each stage of low-pressure cylinder, so that the steam extraction of the low-pressure cylinder 11 is reduced, more steam enters the condenser 12 after doing work, the low-pressure cylinder 11 does work and increases, the unit realizes rapid load increasing action, the liquid level of the condenser 12 rises after more steam enters the condenser 12, the cold water storage of the cold water supply tank 2 connected with the side port of the hot well of the condenser 12 is condensed to prevent the liquid level of the condenser 12 from being too high, the liquid level of the deaerator 13 drops due to the reduction of the water supply amount, and at the moment, the.

2) When the load is reduced by adopting the water supplementing tank adjusting system, part of the exhaust steam of the high-pressure cylinder 10 enters the jet type heat pump 3, the rest of the exhaust steam enters the low-pressure cylinder 11, so that the steam inlet amount of the low-pressure cylinder 11 is reduced, the steam enters the low-pressure cylinder 11 to do work and is reduced, the unit realizes the rapid load reduction action, the high-temperature and high-pressure exhaust steam of the high-pressure cylinder 10 enters the jet type heat pump 3 to heat low-temperature water in the cold supplementing water tank 2, and the mixed high-temperature water is driven to enter the hot supplementing water tank.

3) The invention adopts the injection heat pump 3 as the water replenishing tank adjusting system, provides heat and power by utilizing the steam exhausted by the high pressure cylinder 10, heats and drives the low-temperature water in the cold replenishing water tank 2 to enter the hot replenishing water tank 1, reduces the service power, has simple equipment structure and improves the economy.

Drawings

FIG. 1 shows a flexibility adjusting system of coal-fired units adopting water replenishing tanks

In the figure, a hot water replenishing tank 1, a cold water replenishing tank 2, a jet heat pump 3, a water feeding pump at the 4 th position, a throttle valve at the 5 th position, a second throttle valve 6, a third throttle valve 7, a second water feeding pump 8, a steam valve 9, a high-pressure cylinder 10, a low-pressure cylinder 11, a condenser 12, a deaerator 13, a boiler 14, a third water feeding pump 15, a high-pressure heat exchanger 16 and a low-pressure heat exchanger 17.

Detailed Description

The invention is further described in detail below with reference to the drawings.

As shown in figure 1, a boiler 14 is connected with an inlet of a high-pressure cylinder 10, each stage of steam extraction ports of the high-pressure cylinder 10 are respectively connected with a steam extraction inlet of a corresponding high-pressure heat exchanger 16, a steam exhaust port of the high-pressure cylinder 10 is connected with an inlet of a low-pressure cylinder 11, each stage of steam extraction ports of the low-pressure cylinder 11 are respectively connected with a steam extraction inlet of a corresponding low-pressure heat exchanger 17, a steam exhaust port of the low-pressure cylinder 11 is connected with an inlet of a condenser 12, a water supply outlet of the condenser 12 is connected with a water supply inlet of the low-pressure heat exchanger 17, the low-pressure heat exchanger 17 is connected in series, an outlet of the low-pressure heat exchanger 17 is connected with a water supply fifth inlet of a deaerator 13, an outlet of the deaerator 13 is connected with a water supply inlet of the high-pressure heat exchanger 16, the high-pressure heat exchanger 16 is connected in series, an outlet of the high-pressure heat exchanger 16 is connected with a water supply inlet of the boiler 14, a steam exhaust port of the high-pressure cylinder 10 is also respectively connected with a steam inlet of the deaerator 13 and a water supply inlet of a secondary inlet of an injection type heat pump 3, a 3-1 steam supply water tank, a secondary water supply tank is connected with a secondary water supply throttle valve 3, a secondary water tank 3, a secondary water supply tank 7 is arranged in the water tank, a secondary water supply tank 3-7 injection throttle valve is arranged between the high-3.

When the system rapidly increases the load, the th throttle valve 5 is opened, the second throttle valve 6, the third throttle valve 7 and the steam valve 9 are closed, the second water feed pump 8 starts to work, the th water feed pump 4 is adjusted to be small in opening, the main water supply quantity at the outlet of the condenser 12 is reduced, the heat required by heating water by the low-pressure heat exchanger 17 is reduced, the heat exchange heat comes from steam extraction of each stage of the low-pressure cylinder 11, therefore, the backheating steam extraction quantity of each stage of the low-pressure cylinder 11 is reduced, more steam does work and enters the condenser 12, the low-pressure cylinder 11 does more work, the liquid level of the hot well of the condenser 12 rises, as the th throttle valve 5 is opened, the cold water replenishing tank 2 adjusts the liquid level of the condenser 12, condensed water enters the cold water replenishing tank 2 for storing water, the main water supply quantity is reduced, the liquid level of the deaerator 13 is reduced, the second water feed pump 8 drives high-temperature water in the hot water replenishing tank 1 to enter the deaerator 13, the deaerator 13 is maintained to stabilize.

When the system rapidly reduces the load, the second throttle valve 6, the third throttle valve 7 and the steam valve 9 are opened, the throttle valve 5 is closed, the feed water pump 4 is fully opened, the second feed water pump 8 is closed, because the steam valve 9 is opened, part of steam exhausted by the high-pressure cylinder 10 enters the times inlet 3-1 of the jet type heat pump 3, the rest of steam exhausted by the high-pressure cylinder enters the low-pressure cylinder 11, the steam amount entering the low-pressure cylinder 11 is reduced, the work of the low-pressure cylinder 11 is reduced, the second throttle valve 6 is opened, high-temperature high-pressure steam enters the times inlet 3-1 of the jet type heat pump 3, low-temperature water in the cold water replenishing tank 2 enters the secondary inlet 3-2 of the jet type heat pump 3, the jet type heat pump 3 utilizes the high-temperature high-pressure steam exhausted by the high-pressure cylinder 10 to heat low-temperature water in the cold water replenishing tank 2, the mixed high-temperature water is injected into the hot water replenishing.

The invention adds an external water replenishing tank adjusting system on the basis of the original regenerative system, realizes the quick load lifting of the unit, simultaneously stores the redundant heat in the load lifting process by taking the replenishing water as a medium, and returns the redundant heat to the system in the load lifting process, has simple equipment structure, and improves the flexibility and the economy of the unit.