Air cooling island anti-freezing system under direct air cooling unit cylinder cutting working condition

Abstract

The utility model relates to an air cooling island anti-freezing system under the cylinder switching working condition of a direct air cooling unit. The air cooling island anti-freezing system comprises a medium-pressure cylinder, a low-pressure cylinder, a first generator, a steam exhaust device, an air cooling island, an electric boiler and a heat supply network initial station. A steam outlet of the medium-pressure cylinder and a steam inlet of the low-pressure cylinder are communicated with a first pipeline and a second pipeline; a heat supply pipeline is communicated between a steam outlet of the medium-pressure cylinder and a steam inlet of the heat supply network initial station; a steam outlet of the low-pressure cylinder is communicated with a main steam inlet of the steam exhaust device, and the steam exhaust device is communicated with the air cooling island; a steam outlet of the electric boiler and a main steam inlet of the steam exhaust device are communicated with a third pipeline, and a temperature and pressure reducing device is arranged on the third pipeline. According to the system, the steam inlet amount of the air cooling island is increased through the electric boiler, the situation that pipelines in the air cooling island are frozen is avoided, stable operation of the air cooling island is guaranteed, meanwhile, the heat supply capacity of the system can be improved, and the electric heating contradiction is relieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to direct air cooling unit technical field, in particular to a kind of air cooling island freeze-proof system under direct air cooling unit cylinder cutting condition. BACKGROUND

[0002] New energy grid-connected power generation installed capacity continues to grow rapidly, and the contradiction between thermal power and electricity in the three-north region is prominent. At the same time, the state's requirement for coal-fired units to participate in the deep peak regulation of the power grid is becoming higher and higher. In order to adapt to the new situation of power development and actively respond to the state policy, coal-fired power plants actively promote flexible transformation, such as condensing extraction back heating technology transformation (cutting low-pressure cylinder steam admission), adding electric boiler, hot water storage tank and other equipment.

[0003] Among them, part of the direct air cooling unit uses condensing extraction back heating technology to reduce power generation output while improving heating extraction capacity. However, under the cylinder cutting operating condition of the direct air cooling unit, the low-pressure cylinder steam admission is greatly reduced, and the steam admission of the exhaust device is also reduced synchronously. It is difficult to meet the minimum antifreeze flow requirement of the exhaust steam entering the air cooling island in extremely cold period. UTILITY MODEL CONTENT

[0004] The utility model provides a kind of air cooling island freeze-proof system under direct air cooling unit cylinder cutting condition, the steam admission of air cooling island is increased by electric boiler, avoid the situation that the pipe in air cooling island freezes, ensure the stable operation of air cooling island, can also increase the heating capacity of system, relieve the contradiction between electricity and heat.

[0005] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0006] An air cooling island freeze-proof system under direct air cooling unit cylinder cutting condition, comprising a medium-pressure cylinder, a low-pressure cylinder, a first generator, an exhaust device, an air cooling island, an electric boiler and a heat network head station.

[0007] The steam outlet of the medium-pressure cylinder is communicated with the steam inlet of the low-pressure cylinder by a first pipe and a second pipe.

[0008] The steam outlet of the medium-pressure cylinder is communicated with the steam inlet of the heat network head station by a heating pipe.

[0009] The steam outlet of the low-pressure cylinder is communicated with the main steam inlet of the exhaust device, and the exhaust device is communicated with the air cooling island.

[0010] The steam outlet of the electric boiler is communicated with the main steam inlet of the exhaust device by a third pipe, and a temperature and pressure reducing device is arranged on the third pipe.

[0011] Preferably, it further comprises a heat exchange subsystem.

[0012] The steam outlet of the electric boiler is communicated with the steam inlet of the heat exchange subsystem through a fourth pipeline, and the steam outlet of the electric boiler is communicated with the main steam inlet of the steam exhaust device through a fifth pipeline.

[0013] Preferably, the third pipeline and the fourth pipeline are respectively provided with a first control valve and a second control valve.

[0014] Preferably, the heat exchange subsystem comprises a screw machine and a second generator, and the screw machine and the second generator are coaxially arranged.

[0015] The steam inlet of the screw machine is communicated with the fourth pipeline, and the steam outlet of the screw machine is communicated with the fifth pipeline.

[0016] Preferably, the steam outlet of the electric boiler is communicated with the first station of the heat network.

[0017] Preferably, the steam outlet of the first station of the heat network is communicated with the backwater pipeline of the electric boiler.

[0018] Preferably, the temperature and pressure reducing device is a temperature and pressure reducing valve.

[0019] Compared with the prior art, the utility model has the beneficial effects that:

[0020] In the extremely cold period of winter, when the direct air-cooled unit is deeply peak-regulated, the medium-pressure cylinder extracts steam outward for heating, the exhaust capacity of the low-pressure cylinder is reduced, the steam entering the air-cooled island is reduced, the exhaust capacity entering the air-cooled island is supplemented through the electric boiler, so that the minimum anti-freezing flow of the air-cooled island is met, thereby avoiding the pipe icing in the air-cooled island, and ensuring the stable operation of the air-cooled island. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description, and obviously, the drawings in the following description are some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0022] Figure 1 It is a system schematic diagram of the embodiment in the utility model.

[0023] Explanation of reference signs:

[0024] 1, medium pressure cylinder; 2, low pressure cylinder; 3, first generator; 4, exhaust device; 5, air cooling island; 6, electric boiler; 7, heat network first station; 8, screw machine; 9, second generator; 10, first pipeline; 11, second pipeline; 12, heat supply pipeline; 13, third pipeline; 14, fourth pipeline; 15, fifth pipeline; 16, temperature and pressure reducing device; 17, first control valve; 18, second control valve. DETAILED DESCRIPTION

[0025] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0026] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements inside. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] As Figure 1The utility model discloses an air cooling island anti -freezing system under the cylinder cutting working condition of direct air cooling unit, specifically includes medium pressure cylinder 1, low pressure cylinder 2, first generator 3, exhaust device 4, air cooling island 5, electric boiler 6 and heat network first station 7, wherein medium pressure cylinder 1, low pressure cylinder 2, first generator 3 coaxial arrangement, the steam outlet of medium pressure cylinder 1 is communicated with the steam inlet of low pressure cylinder 2 with first pipeline 10 and second pipeline 11, first pipeline 10 and second pipeline 11 all are provided with control valve, the steam outlet of medium pressure cylinder 1 and the steam inlet of heat network first station 7 are communicated with heat supply pipeline, heat supply pipeline also is provided with control valve, the steam outlet of low pressure cylinder 2 and the main steam inlet of exhaust device 4 are communicated, and exhaust device 4 is communicated with air cooling island 5. Specifically, first pipeline 10 is set as normal steam pipeline (when air cooling unit is normal), and second pipeline 11 is set as small flow pipeline, and is used when air cooling unit is used to adopt condensing extraction back heating technology to reduce the power generation output and improve the heating extraction capacity (cut cylinder carries out depth peak regulation);Specifically, when air cooling unit is normal, the control valve on heat supply pipeline and second pipeline 11 is closed, and the control valve on first pipeline 10 is opened, and the steam of medium pressure cylinder 1 normally enters low pressure cylinder 2 through first pipeline 10, then the exhaust is entered into air cooling island 5 through exhaust device 4;When air cooling unit needs to participate in peak regulation, reduces the power generation output and improves the heating capacity, the control valve on heat supply pipeline and second pipeline 11 is opened, and the control valve on first pipeline 10 is closed, so that a part of steam enters heat network first station 7 and exchanges heat from heat supply pipeline 12, a small part of steam enters low pressure cylinder 2 and generates electricity and does work through second pipeline 11, and the exhaust enters air cooling island 5, to improve the heating capacity and reduce the power generation capacity.

[0029] To avoid the situation that the minimum anti-freezing flow of air cooling island 5 is not met due to the exhaust capacity in low pressure cylinder 2 when air cooling unit adopts condensing extraction back heating technology to reduce the power generation output and improve the heating extraction capacity (cut cylinder carries out depth peak regulation) in the extremely cold period of winter, the system further comprises an electric boiler 6, wherein the electric boiler 6 is a commonly used device for unit peak regulation in a power plant, and the electric boiler 6 is applied to the system, specifically, the steam outlet of the electric boiler 6 is communicated with the main steam inlet of the exhaust device 4 through a third pipeline 13, and a desuperheating and pressure reducing device 16 is arranged on the third pipeline 13, in the above working scenario, the electric boiler 6 generates steam to enter the third pipeline 13, and then the steam quality of the steam obtained through the desuperheating and pressure reducing device 16 is similar to that of the steam discharged from the steam outlet of the low pressure cylinder 2, so that the steam enters the exhaust device 4, and then enters the air cooling island 5 together with the exhaust of the low pressure cylinder 2, thereby increasing the steam quantity entering the air cooling island 5, so that the minimum anti-freezing flow of the air cooling island 5 is met, and the situation that the pipes in the air cooling island 5 are frozen is avoided, and the stable operation of the air cooling island 5 is ensured. Specifically, the desuperheating and pressure reducing device 16 can be a desuperheating and pressure reducing valve.

[0030] Specifically, in order to utilize the steam energy discharged by the electric boiler 6 and avoid energy loss after the steam passes through the desuperheating and pressure reducing valve device, the system further comprises a heat exchange subsystem, the steam outlet of the electric boiler 6 is communicated with the steam inlet of the heat exchange subsystem through a fourth pipeline 14, and the steam outlet of the electric boiler 6 is communicated with the main steam inlet of the steam exhaust device 4 through a fifth pipeline 15, the steam generated by the electric boiler 6 can be heat-exchanged with the medium in the heat exchange subsystem, so as to reduce the quality of the steam, so that the quality of the steam discharged from the steam outlet of the low-pressure cylinder 2 is similar to that of the steam, the requirement of the air cooling island 5 for the entering steam is met, and the waste of steam energy is avoided.

[0031] Therefore, in the embodiment, two steam supply paths are arranged between the steam exhaust outlet of the electric boiler 6 and the main steam inlet of the steam exhaust device 4, one of which is directly communicated, and the steam generated by the electric boiler 6 directly passes through the third pipeline 13, enters the steam exhaust device 4 through the desuperheating and pressure reducing device 16, and the other of which is that the steam generated by the electric boiler 6 is heat-exchanged with the heat exchange subsystem first, and then enters the steam exhaust device 4, of course, the two paths are switched according to the specific working condition, of course, in order to realize the switching and use of the two paths, the first control valve 17 and the second control valve 18 are arranged on the third pipeline 13 and the fourth pipeline 14 respectively, and are both electromagnetic valves, the switching is realized by controlling the first control valve 17 and the second control valve 18, and the operation is convenient.

[0032] Specifically, the heat exchange subsystem comprises a screw machine 8 and a second generator 9, wherein the screw machine 8 and the second generator 9 are coaxially arranged, the steam inlet of the screw machine 8 is communicated with the third pipeline 13, and the steam outlet of the screw machine 8 is communicated with the fifth pipeline 15, so that the steam generated by the electric boiler 6 enters the screw machine 8 through the third pipeline 13, acts as a heat source, and drives the screw machine 8 to work, and then drives the second generator 9 to generate electricity, generates a part of electric energy, supplies the external use, and also reduces the quality of the steam.

[0033] The steam outlet of the electric boiler 6 is communicated with the heat network first station 7, so that the condensing extraction back heating technology is adopted in the whole air cooling unit to reduce the power generation output and improve the steam extraction capacity at the same time (cylinder switching is used for deep peak regulation), the steam quantity entering the heat network first station 7 is further increased by the electric boiler 6, the heat exchange capacity of the heat network first station 7 is increased, and the heat supply capacity of the whole system during peak regulation is improved.

[0034] Specifically, the steam outlet of the heat network first station 7 is communicated with the water return pipeline of the electric boiler 6, and the water formed after heat exchange enters the water return pipeline of the electric boiler 6 from the steam outlet, so as to supply water for the electric boiler 6 to generate steam.

[0035] The above-mentioned embodiment is only a preferred embodiment of the utility model, and cannot be used to limit the range of protection of the utility model, and any non-substantial change and replacement made by the person skilled in the art on the basis of the utility model belongs to the range of protection required by the utility model.

Claims

1. An air cooling island antifreeze system for a direct air cooling unit under cylinder cutting conditions, characterized in that: It includes the medium-pressure cylinder, low-pressure cylinder, first generator, steam exhaust device, air-cooling island, electric boiler and the first station of the heating network; The steam outlet of the intermediate pressure cylinder and the steam inlet of the low pressure cylinder are connected via a first pipe and a second pipe; A heat supply pipeline is connected between the steam outlet of the intermediate pressure cylinder and the steam inlet of the first station of the heat network; The steam outlet of the low-pressure cylinder is connected to the main steam inlet of the exhaust device, and the exhaust device is connected to the air-cooling island; The steam outlet of the electric boiler and the main steam inlet of the exhaust device are connected via a third pipeline, and a temperature and pressure reduction device is provided on the third pipeline.

2. The antifreeze system according to claim 1, characterized in that: It also includes a heat exchange subsystem; The steam outlet of the electric boiler is connected to the steam inlet of the heat exchange subsystem via a fourth pipe, and the steam outlet of the electric boiler is connected to the main steam inlet of the exhaust device via a fifth pipe.

3. The antifreeze system according to claim 2, characterized in that: The third pipeline and the fourth pipeline are respectively provided with a first control valve and a second control valve.

4. The antifreeze system according to claim 2, characterized in that: The heat exchange subsystem includes a screw machine and a second generator, and the screw machine and the second generator are coaxially arranged; The steam inlet of the screw machine is communicated with the fourth pipeline, and the steam outlet of the screw machine is communicated with the fifth pipeline.

5. The antifreeze system according to claim 1, characterized in that: The steam outlet of the electric boiler is connected to the first station of the heating network.

6. The antifreeze system according to claim 1, characterized in that: The steam outlet of the first station of the heating network is connected to the return water pipeline of the electric boiler.

7. The antifreeze system according to claim 1, characterized in that: The temperature reduction and pressure reduction device is a temperature reduction and pressure reduction valve.

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