Steam supply device of steam-driven feed water pump and feed water system of thermal power generator set

Abstract

This invention discloses a steam supply device for a steam-driven feedwater pump and a feedwater system for a thermal power generating unit. The steam supply device includes a first steam supply pipeline, a second steam supply pipeline, a pre-set drain pipeline, and a pre-set pipeline. The first steam supply pipeline is connected to the steam-driven feedwater pump and is used to transport steam from a first steam system to the steam-driven feedwater pump. The second steam supply pipeline is connected to the steam-driven feedwater pump and is used to transport steam from a second steam system to the steam-driven feedwater pump. When steam is being transported from the second steam supply pipeline to the steam-driven feedwater pump, the first steam supply pipeline is in a standby state. One end of the pre-set drain pipeline is connected to the first steam supply pipeline, one end of the pre-set pipeline is connected to the pre-set drain pipeline, and the other end is connected to the second steam supply pipeline. This invention allows water accumulated in the first steam supply pipeline to be drained through the pre-set drain pipeline, and steam can enter the second steam supply pipeline through the pre-set pipeline, where it is transported to the steam-driven feedwater pump together with the steam in the second steam supply pipeline, reducing steam waste and improving the thermal efficiency of the unit.

Description

Technical Field

[0001] This invention relates to the field of thermal power generation, and in particular to a steam supply device for a steam-driven feedwater pump. This invention also relates to a feedwater system for a thermal power generating unit. Background Technology

[0002] Each thermal power generating unit is generally equipped with two feedwater pump turbines. In order to meet the needs of operation, the feedwater pump turbines are equipped with two steam sources. During normal operation, the main unit uses the intermediate pressure cylinder exhaust, i.e., the main unit's fourth-stage extraction steam. During low or high load, the main unit uses the high pressure cylinder exhaust (cold section). The intermediate pressure regulating valve and the high pressure regulating valve are controlled by the same hydraulic motor through the lifting plate type steam distribution mechanism.

[0003] During the startup process of the feedwater pump turbine, high-pressure steam is kept on until it reaches approximately 40% of the main unit's rated load; medium-pressure steam enters at 15% of the main unit's rated load; within the range of 15% to 40% of the main unit's rated load, high-pressure steam and medium-pressure steam enter simultaneously; above 40% of the main unit's rated load, all medium-pressure steam enters; below 60% of the main unit's rated load, it can operate as a single pump; above 60% of the main unit's rated load, it operates as a dual pump.

[0004] When the extraction steam pressure of the main unit rises to a level sufficient to open the check valve, the intermediate-pressure steam enters the turbine. The steam distribution mechanism automatically and gradually cuts off the high-pressure steam. This check valve is linked to the main unit extraction steam valve. When the feedwater pump turbine starts up, steam is generally supplied to the intermediate-pressure side of the feedwater pump turbine from the auxiliary steam source. When the turbine is connected to the grid and receives 15% of its rated load, the intermediate-pressure steam is supplied by the fourth-stage extraction steam of the unit, and the high-pressure steam is supplied by the cold storage. After the unit is operating normally, the high-pressure steam inlet is in standby mode.

[0005] Because the high-pressure steam inlet is in standby mode during normal unit operation, it must be immediately activated in case of a fault in the intermediate-pressure steam process system (e.g., valve detachment, sudden changes in operating conditions) to ensure the feedwater pump turbine does not lose its power source and maintains stable power output. The main problem is that the long-term standby status of the high-pressure steam source in the feedwater pump turbine may lead to water carryover, affecting the safe operation of the turbine. To avoid this and ensure the high-pressure steam inlet is in hot standby mode, drain valves connected to the high-pressure steam supply pipeline are opened periodically or long-term to warm the pipeline and prevent water accumulation. However, draining water wastes high-pressure steam and reduces the unit's thermal efficiency. Therefore, optimized design is needed to make the unit more energy-efficient and improve its thermal efficiency. Summary of the Invention

[0006] The purpose of this invention is to provide a steam supply device for a steam-driven feedwater pump, which can reduce steam waste and help improve the thermal efficiency of the unit. This invention also provides a feedwater system for a thermal power generating unit.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A steam supply device for a steam-driven feedwater pump, comprising:

[0009] The first steam supply pipeline is connected to the steam-driven feedwater pump and is used to transport the steam from the first steam system to the steam-driven feedwater pump.

[0010] The second steam supply pipeline is connected to the steam-driven feedwater pump and is used to transport steam from the second steam system to the steam-driven feedwater pump. When steam is being transported from the second steam supply pipeline to the steam-driven feedwater pump, the first steam supply pipeline is shut off and in standby mode.

[0011] A pre-installed drainage pipe is provided, one end of which is connected to the first steam supply pipe;

[0012] A pre-set pipe is connected at one end to the pre-set drainage pipe and at the other end to the second steam supply pipe.

[0013] Optionally, a first steam valve is provided at the end of the first steam supply pipeline connected to the steam-driven feedwater pump;

[0014] It also includes: a first drainage pipe, one end of which is connected to the portion of the first steam supply pipe located between the first steam valve and the steam-driven feedwater pump, the first drainage pipe serving as the preset drainage pipe.

[0015] Optionally, it further includes: a second drain pipe, one end of which is connected to the portion of the first steam supply pipe located between the first steam valve and the first steam system.

[0016] Optionally, a first steam valve is provided at the end of the first steam supply pipeline connected to the steam-driven feedwater pump;

[0017] It also includes: a second drain pipe, one end of which is connected to the portion of the first steam supply pipe located between the first steam valve and the first steam system, the second drain pipe serving as the preset drain pipe.

[0018] Optionally, the preset drainage pipe includes a first end and a second end, the first end is connected to the first steam supply pipe, the second end extends out, and one end of the preset pipe is connected to a preset position of the preset drainage pipe;

[0019] A first valve is provided in the portion between the first end of the preset drainage pipe and the preset position.

[0020] Optionally, the preset drainage pipe includes a first end and a second end, the first end is connected to the first steam supply pipe, the second end extends out, and one end of the preset pipe is connected to a preset position of the preset drainage pipe;

[0021] A second valve is provided in the portion between the preset position and the second end of the preset drainage pipe.

[0022] Optionally, a preset valve is provided on the preset pipeline.

[0023] Optionally, a second steam valve is provided at one end of the second steam supply pipeline connected to the steam-driven feedwater pump, and the preset pipeline is connected to the portion of the second steam supply pipeline between the second steam valve and the second steam system.

[0024] Optionally, a second steam valve is provided at one end of the second steam supply pipeline connected to the steam-driven feedwater pump;

[0025] Also includes:

[0026] The third drainage pipe is connected at one end to the portion of the second steam supply pipe located between the second steam valve and the steam-driven feedwater pump.

[0027] Or / and a fourth drain pipe, one end of which is connected to the portion of the second steam supply pipe located between the second steam valve and the second steam system.

[0028] A water supply system for a thermal power generating unit, comprising:

[0029] Steam-driven feedwater pump;

[0030] A steam supply device for the steam-driven feedwater pump described in any of the above-mentioned embodiments, connected to the steam-driven feedwater pump.

[0031] As can be seen from the above technical solution, the steam supply device for a steam-driven feedwater pump provided by the present invention includes a first steam supply pipe, a second steam supply pipe, a preset drain pipe, and a preset pipe. The first steam supply pipe is connected to the steam-driven feedwater pump and is used to transport steam from a first steam system to the steam-driven feedwater pump. The second steam supply pipe is connected to the steam-driven feedwater pump and is used to transport steam from a second steam system to the steam-driven feedwater pump. When steam is being supplied to the steam-driven feedwater pump from the second steam supply pipe, the first steam supply pipe is shut off and is in a standby state. One end of the preset drain pipe is connected to the first steam supply pipe, one end of the preset pipe is connected to the preset drain pipe, and the other end is connected to the second steam supply pipe. In the steam supply device of the steam-driven feedwater pump of the present invention, when steam is supplied to the steam-driven feedwater pump from the second steam supply pipeline, the first steam supply pipeline is shut off and in a standby state. Water accumulated in the first steam supply pipeline can be drained through a pre-set drainage pipeline. Steam in the first steam supply pipeline can then enter the second steam supply pipeline through the pre-set pipeline and be supplied to the steam-driven feedwater pump together with the steam in the second steam supply pipeline, reducing the waste of steam in the first steam supply pipeline. Therefore, the steam supply device of the steam-driven feedwater pump of the present invention can reduce steam waste and help improve the thermal efficiency of the unit.

[0032] The present invention also provides a water supply system for a thermal power generating unit, which can achieve the above-mentioned beneficial effects. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of a steam supply device for a steam-driven feedwater pump according to an embodiment of the present invention;

[0035] Figure 2 for Figure 1 The diagram shows the flow direction of steam or water in each pipe of the steam supply device of the steam-driven feedwater pump.

[0036] Figure 3 A schematic diagram of a steam supply device for a steam-driven feedwater pump provided in another embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of a steam supply device for a steam-driven feedwater pump, provided in another embodiment of the present invention.

[0038] The reference numerals in the accompanying drawings include:

[0039] 100-Steam-driven feedwater pump, 101-First steam supply pipeline, 102-Second steam supply pipeline, 103-First steam valve, 104-Second steam valve, 105-First drain pipeline, 106-Second drain pipeline, 107-Third drain pipeline, 108-Fourth drain pipeline, 109-First preset pipeline, 110-Second preset pipeline, 111-First preset valve, 112-Second preset valve, 113-First valve, 114-Second valve. Detailed Implementation

[0040] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0041] This embodiment provides a steam supply device for a steam-driven feedwater pump, including:

[0042] The first steam supply pipeline is connected to the steam-driven feedwater pump and is used to transport the steam from the first steam system to the steam-driven feedwater pump.

[0043] The second steam supply pipeline is connected to the steam-driven feedwater pump and is used to transport steam from the second steam system to the steam-driven feedwater pump. When steam is being transported from the second steam supply pipeline to the steam-driven feedwater pump, the first steam supply pipeline is shut off and in standby mode.

[0044] A pre-installed drainage pipe is provided, one end of which is connected to the first steam supply pipe;

[0045] A pre-set pipe is connected at one end to the pre-set drainage pipe and at the other end to the second steam supply pipe.

[0046] Steam is supplied to the steam-driven feedwater pump through the first or second steam supply pipeline, so that the steam turbine corresponding to the steam-driven feedwater pump can do work.

[0047] In this embodiment of the steam supply device for the steam-driven feedwater pump, when steam is supplied to the steam-driven feedwater pump from the second steam supply pipeline, the first steam supply pipeline is shut off and in a standby state. If the first steam supply pipeline remains in a standby state for a long time, water may be carried over into the steam due to the lack of steam flow. In this steam supply device, a pre-set drainage pipe can drain the accumulated water in the first steam supply pipeline. The steam in the first steam supply pipeline can then enter the second steam supply pipeline through the pre-set pipe and be supplied to the steam-driven feedwater pump together with the steam in the second steam supply pipeline. This reduces the waste of steam in the first steam supply pipeline. Therefore, the steam supply device for the steam-driven feedwater pump in this embodiment can reduce steam waste and, when applied to thermal power generating units, helps to improve the thermal efficiency of the unit.

[0048] In some embodiments, a first steam valve is provided at the end of the first steam supply pipeline connected to the steam-driven feedwater pump; the steam supply device of this steam-driven feedwater pump further includes: a first drain pipe, one end of which is connected to the portion of the first steam supply pipeline between the first steam valve and the steam-driven feedwater pump, the first drain pipe serving as the preset drain pipe. The first steam valve is used to control the supply of steam from the first steam supply pipeline to the steam-driven feedwater pump. When steam is supplied to the steam-driven feedwater pump from the second steam supply pipeline, the first steam valve can be closed, shutting off the first steam supply pipeline and placing it in a standby state. If the first steam supply pipeline is in a standby state for a long time, the steam in the portion of the first steam supply pipeline between the first steam valve and the steam-driven feedwater pump will carry water. The accumulated water in this portion of the first steam supply pipeline can be drained through the first drain pipe, and the steam in this portion of the first steam supply pipeline can enter the second steam supply pipeline through the preset pipe. For an example, refer to [reference needed]. Figure 1 and Figure 2 , Figure 1This is a schematic diagram of a steam supply device for a steam-driven feedwater pump according to one embodiment. Figure 2 for Figure 1 The diagram shows the flow direction of steam or water in each pipe of the steam supply device of the steam-driven feedwater pump. As shown in the figure, the first steam supply pipe 101 is connected to the steam-driven feedwater pump 100, and the first steam supply pipe 101 is equipped with a first steam valve 103. One end of the first drain pipe 105 is connected to the portion of the first steam supply pipe 101 between the first steam valve 103 and the steam-driven feedwater pump 100. One end of the first pre-set pipe 109 is connected to the first drain pipe 105, and the other end is connected to the second steam supply pipe 102.

[0049] Furthermore, the steam supply device of this steam-driven feedwater pump may also include: a second drain pipe, one end of which is connected to the portion of the first steam supply pipe 101 located between the first steam valve 103 and the first steam system. (See reference...) Figure 1 As shown, if the first steam supply pipeline 101 is in standby mode for a long time, the steam in the part of the first steam supply pipeline 101 between the first steam valve 103 and the first steam system will carry water. The water in this part of the first steam supply pipeline 101 can be discharged through the second drain pipeline 106 to prevent the water in the first steam supply pipeline 101 from entering the steam-driven feedwater pump 100 when the first steam supply pipeline 101 is started and steam is supplied to the steam-driven feedwater pump 100 through the first steam supply pipeline 101, thus affecting the safe operation of the turbine corresponding to the steam-driven feedwater pump.

[0050] In the steam supply device of the steam-driven feedwater pump in this embodiment, drainage pipes are respectively installed before and after the first steam valve 103 on the first steam supply pipe 101. This allows the accumulated water in the first steam supply pipe 101 before the first steam valve 103 to be drained, and also allows the accumulated water in the first steam supply pipe 101 after the first steam valve 103 to be drained. This ensures that when the first steam supply pipe 101 is activated and steam is supplied to the steam-driven feedwater pump 100 through the first steam supply pipe 101, the steam is free of water, thus ensuring the safe operation of the steam turbine corresponding to the steam-driven feedwater pump.

[0051] In some embodiments, a first steam valve 103 is provided at the end of the first steam supply pipeline 101 connected to the steam-driven feedwater pump 100; the steam supply device of this steam-driven feedwater pump further includes: a second drain pipe, one end of which is connected to the portion of the first steam supply pipeline 101 between the first steam valve 103 and the first steam system, the second drain pipe serving as the preset drain pipe. The first steam valve 103 is used to control the supply of steam from the first steam supply pipeline 101 to the steam-driven feedwater pump 100. When steam is supplied to the steam-driven feedwater pump 100 by the second steam supply pipeline 102, the first steam valve 103 can be closed, causing the first steam supply pipeline 101 to be shut off and in a standby state. If the first steam supply pipeline 101 is in standby mode for an extended period, the steam in the portion of the first steam supply pipeline 101 between the first steam valve 103 and the first steam system will carry water. This accumulated water can be drained through the second drain pipe 106. Furthermore, the steam in this portion of the first steam supply pipeline 101 can enter the second steam supply pipeline 102 through a pre-set pipe, and can be transported to the steam-driven feedwater pump 100 along with the steam in the second steam supply pipeline 102. An example can be found by referring to... Figure 3 , Figure 3 A schematic diagram of a steam supply device for a steam-driven feedwater pump is provided in another embodiment. As shown in the figure, a first steam supply pipe 101 is connected to a steam-driven feedwater pump 100, and a first steam valve 103 is provided on the first steam supply pipe 101. One end of a second drain pipe 106 is connected to the portion of the first steam supply pipe 101 between the first steam valve 103 and the first steam system. One end of a second pre-set pipe 110 is connected to the second drain pipe 106, and the other end is connected to the second steam supply pipe 102.

[0052] If the steam pressure delivered by the first steam supply pipe 101 is higher than the steam pressure delivered by the second steam supply pipe 102, for example, the first steam system delivers high-pressure steam and sends it to the steam-driven feedwater pump 100 through the first steam supply pipe 101, and the second steam system delivers medium-pressure steam and sends it to the steam-driven feedwater pump 102 through the second steam supply pipe 102, in this case, the preset pipe connects the second drain pipe 106 and the second steam supply pipe 102. The second drain pipe 106 is connected to the part of the first steam supply pipe 101 between the first steam valve 103 and the first steam system. In this case, the steam pressure in the second drain pipe 106 is higher than the steam pressure in the second steam supply pipe 102. To address this, the second preset pipe 110 can be equipped with a pressure reducing device so that the steam in the second drain pipe 106 is delivered to the second steam supply pipe 102 after pressure reduction. This avoids the direct transmission of steam from the second drain pipe 106 to the second steam supply pipe 102 via the second preset pipe 110, which could cause a reverse impact of steam on the turbine and pose a danger. The pressure reducing device can be, but is not limited to, a regulating valve.

[0053] In some embodiments, a first steam valve 103 is provided at the end of the first steam supply pipeline 101 connected to the steam-driven feedwater pump 100; the steam supply device of this steam-driven feedwater pump also includes:

[0054] The first drainage pipe 105 is connected at one end to the portion of the first steam supply pipe 101 located between the first steam valve 103 and the steam-driven water pump 100.

[0055] The first preset pipe has one end connected to the first drainage pipe 105 and the other end connected to the second steam supply pipe 102.

[0056] The second drainage pipe 106 is connected at one end to the portion of the first steam supply pipe 101 located between the first steam valve 103 and the first steam system.

[0057] The second preset pipe has one end connected to the second drainage pipe 106 and the other end connected to the second steam supply pipe 102.

[0058] For example, refer to Figure 4 , Figure 4 A schematic diagram of a steam supply device for a steam-driven feedwater pump is provided in another embodiment. As shown in the figure, one end of a first preset pipe 109 is connected to a first drain pipe 105, and the other end is connected to a second steam supply pipe 102. The first drain pipe 105 can drain the water accumulated in the portion of the first steam supply pipe 101 between the first steam valve 103 and the steam-driven feedwater pump 100, and the steam in this portion of the first steam supply pipe 101 can enter the second steam supply pipe 102 through the first preset pipe 109. One end of a second preset pipe 110 is connected to a second drain pipe 106, and the other end is connected to the second steam supply pipe 102. The second drain pipe 106 can drain the water accumulated in the portion of the first steam supply pipe 101 between the first steam valve 103 and the first steam system, and the steam in this portion of the first steam supply pipe 101 can enter the second steam supply pipe 102 through the second preset pipe 110.

[0059] In the steam supply device of the steam-driven feedwater pump in this embodiment, drainage pipes are respectively provided in front of the first steam valve 103 and after the first steam valve 103 on the first steam supply pipe 101, so that the accumulated water in the first steam supply pipe 101 in front of the first steam valve 103 can be discharged, and the accumulated water in the first steam supply pipe 101 after the first steam valve 103 can also be discharged. Furthermore, a first preset pipe 109 is provided to connect the first drain pipe 105 before the first steam valve 103 on the first steam supply pipe 101 to the second steam supply pipe 102, and a second preset pipe 110 is provided to connect the second drain pipe 106 after the first steam valve 103 on the first steam supply pipe 101 to the second steam supply pipe 102. This allows the steam in front of the first steam valve 103 on the first steam supply pipe 101 to enter the second steam supply pipe 102 through the first preset pipe 109, preventing this part of the steam from being discharged and wasted along the first drain pipe 105, and also allows the steam in behind the first steam valve 103 on the first steam supply pipe 101 to enter the second steam supply pipe 102 through the second preset pipe 110, preventing this part of the steam from being discharged and wasted along the second drain pipe 106.

[0060] Preferably, in the above embodiments, the preset drain pipe includes a first end and a second end. The first end is connected to the first steam supply pipe 101, and the second end extends outward. One end of the preset pipe is connected to a preset position of the preset drain pipe. A first valve is provided in the portion between the first end and the preset position of the preset drain pipe. The first valve can control the on / off state of the preset drain pipe, facilitating switching operations. The first valve forms an isolation valve on the preset drain pipe. Optionally, the first valve can regulate the steam flow rate.

[0061] Preferably, in the above embodiments, the preset drainage pipe includes a first end and a second end. The first end is connected to the first steam supply pipe 101, and the second end extends outward. One end of the preset pipe is connected to a preset position of the preset drainage pipe. A second valve is provided in the portion between the preset position of the preset drainage pipe and the second end. The second valve can be used to control the drainage of water accumulated in the preset drainage pipe.

[0062] Preferably, in the above embodiments, a preset valve is provided on the preset pipeline. The preset valve controls the opening and closing of the preset pipeline. Optionally, the preset valve can adjust the steam flow rate.

[0063] Further in the above embodiments, a second steam valve is provided at the end of the second steam supply pipeline 102 connected to the steam-driven feedwater pump 100. The preset pipeline and the portion of the second steam supply pipeline 102 between the second steam valve and the second steam system are connected. The second steam valve is used to control the supply of steam from the second steam supply pipeline 102 to the steam-driven feedwater pump 100. See also, for an example... Figure 1 , Figure 2 and Figure 4 As shown, one end of the first preset pipe 109 is connected to the first drain pipe 105, and the other end is connected to the portion of the second steam supply pipe 102 located between the second steam valve 104 and the second steam system. Steam in the first drain pipe 105 enters the second steam supply pipe 102 through the first preset pipe 109, mixes with the steam in the second steam supply pipe 102, and is then transported together to the steam-driven feedwater pump 100 to perform work on the corresponding steam turbine. (See reference...) Figure 3 and Figure 4 As shown, one end of the second preset pipe 110 is connected to the second drain pipe 106, and the other end is connected to the part of the second steam supply pipe 102 between the second steam valve 104 and the second steam system. The steam in the second drain pipe 106 enters the second steam supply pipe 102 through the second preset pipe 110, mixes with the steam in the second steam supply pipe 102, and is then transported to the steam-driven feedwater pump 100 to do work on the steam turbine corresponding to the steam-driven feedwater pump 100.

[0064] Further, in the above embodiments, the steam supply device of this steam-driven feedwater pump includes a second steam valve at the end of the second steam supply pipeline 102 connected to the steam-driven feedwater pump 100; the steam supply device of this steam-driven feedwater pump also includes: a third drain pipe, one end of which is connected to the portion of the second steam supply pipeline 102 between the second steam valve 104 and the steam-driven feedwater pump 100; or / and a fourth drain pipe, one end of which is connected to the portion of the second steam supply pipeline 102 between the second steam valve 104 and the second steam system. If the second steam supply pipeline 102 is in standby mode for a period of time, the steam in the portion of the second steam supply pipeline 102 between the second steam valve 104 and the steam-driven feedwater pump 100 may carry water, and the accumulated water in this portion of the second steam supply pipeline 102 can be discharged through the third drain pipe, or / and the steam in the portion of the second steam supply pipeline 102 between the second steam valve 104 and the second steam system may carry water, and the accumulated water in this portion of the second steam supply pipeline 102 can be discharged through the fourth drain pipe.

[0065] For example, refer to Figures 1 to 4 As shown in the figure, the second steam supply pipeline 102 is equipped with a second steam valve 104, and also includes a third drain pipeline 107 and a fourth drain pipeline 108. One end of the third drain pipeline 107 is connected to the portion of the second steam supply pipeline 102 between the second steam valve 104 and the steam-driven feedwater pump 100, and one end of the fourth drain pipeline 108 is connected to the portion of the second steam supply pipeline 102 between the second steam valve 104 and the second steam system. The first drain pipeline 105, the second drain pipeline 106, the third drain pipeline 107, and the fourth drain pipeline 108 can be connected to a drain expansion tank, which may be equipped with a condenser.

[0066] A first valve 113 and a second valve 114 are respectively installed in the third drainage pipe 107, the fourth drainage pipe 108, the first drainage pipe 105, and the second drainage pipe 106. A first preset valve 111 is installed in the first preset pipe 109, and a second preset valve 112 is installed in the second preset pipe 110. Figure 1 and Figure 2 The steam supply device shown has the first steam supply pipeline 101 in standby mode when steam is supplied from the second steam supply pipeline 102 to the steam-driven feedwater pump 100. Simultaneously, the first valve 113 and the second valve 114 of the first drain pipeline 105, as well as the first preset valve 111 of the first preset pipeline 109, can be opened. The first valve 113, the second valve 114, and the first preset valve 111 can be opened continuously or periodically, allowing accumulated water in front of the first steam valve 103 on the first steam supply pipeline 101 to be discharged, and steam to enter the second steam supply pipeline 102 through the first preset pipeline 109. Figure 3 The steam supply device shown, when supplying steam from the second steam supply pipe 102 to the steam-driven feedwater pump 100, has the first steam supply pipe 101 in a standby state. Simultaneously, the first valve 113 and the second valve 114 of the second drain pipe 106, as well as the second preset valve 112 of the second preset pipe 110, can be opened, either continuously or periodically. Figure 4 The steam supply device shown has the first steam supply pipe 101 in standby mode when steam is supplied from the second steam supply pipe 102 to the steam-driven feedwater pump 100. The first valve 113 and the second valve 114 of the first drain pipe 105 and the second drain pipe 106, as well as the first preset valve 111 of the first preset pipe 109 and the second preset valve 112 of the second preset pipe 110, can be opened continuously or periodically. When warming up the first steam supply pipe 101, the first valve 113 and the second valve 114 of the first drain pipe 105 and the second drain pipe 106 are closed to prevent steam waste during warming.

[0067] In this embodiment, the steam supply device of the steam-driven feedwater pump can be a cold reheat steam system and a four-stage extraction steam system.

[0068] The first valve 113 can be a steam-driven valve, the second valve 114 can be a manual valve, the first preset valve 111 can be a manual valve, and the second preset valve 112 can be a manual valve. The first steam valve 103 and / or the second steam valve 104 can be regulating valves, capable of regulating the flow rate of steam.

[0069] This embodiment also provides a water supply system for a thermal power generating unit, including:

[0070] Steam-driven feedwater pump;

[0071] A steam supply device for the steam-driven feedwater pump described in any of the above-mentioned embodiments, connected to the steam-driven feedwater pump.

[0072] In the feedwater system of the thermal power generator unit of this embodiment, when steam is supplied to the steam-driven feedwater pump from the second steam supply pipeline, the first steam supply pipeline is shut off and in standby mode. The water in the first steam supply pipeline can be discharged through the preset drain pipeline. The steam in the first steam supply pipeline can enter the second steam supply pipeline through the preset pipeline and be transported to the steam-driven feedwater pump together with the steam in the second steam supply pipeline, thereby reducing the waste of this part of the steam in the first steam supply pipeline. Therefore, it can reduce steam waste and help improve the thermal efficiency of the unit.

[0073] Steam-driven feedwater pumps are crucial process equipment in thermal power generating units, primarily supplying water to the boiler. Powered by steam, these pumps enter a small turbine through a regulating valve, driving the feedwater pump. The pump speed is controlled by adjusting the steam flow rate, thereby regulating the overall feedwater flow of the process system. The feedwater pump's power steam is divided into working steam and standby steam. During normal operation, working steam is supplied, which can be provided by the fourth stage of extraction steam. When the normal steam supply process system fails, standby steam is activated to ensure normal steam supply to the feedwater pump turbine.

[0074] The steam supply device for the steam-driven feedwater pump and the feedwater system for thermal power generating units provided by this invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A steam supply device for a steam-driven feedwater pump, characterized in that, include: The first steam supply pipeline is connected to the steam-driven feedwater pump and is used to transport the steam delivered by the first steam system to the steam-driven feedwater pump. A first steam valve is provided at the end of the first steam supply pipeline connected to the steam-driven feedwater pump. The second steam supply pipeline is connected to the steam-driven feedwater pump and is used to transport steam from the second steam system to the steam-driven feedwater pump. When steam is supplied from the second steam supply pipeline to the steam-driven feedwater pump, the first steam supply pipeline is shut off and in standby mode. A second steam valve is provided at the end of the second steam supply pipeline connected to the steam-driven feedwater pump. A pre-installed drainage pipe is provided, one end of which is connected to the first steam supply pipe; A preset pipe, one end of which is connected to the preset drain pipe, and the other end of which is connected to the second steam supply pipe, wherein the preset pipe and the second steam supply pipe are connected at the portion between the second steam valve and the second steam system; It also includes: a second drain pipe, one end of which is connected to the portion of the first steam supply pipe located between the first steam valve and the first steam system, the second drain pipe serving as the preset drain pipe.

2. The steam supply device for the steam-driven feedwater pump according to claim 1, characterized in that, A first steam valve is provided at the end of the first steam supply pipeline that is connected to the steam-driven feedwater pump; It also includes: a first drainage pipe, one end of which is connected to the portion of the first steam supply pipe located between the first steam valve and the steam-driven feedwater pump, the first drainage pipe serving as the preset drainage pipe.

3. The steam supply device for the steam-driven feedwater pump according to claim 2, characterized in that, Also includes: The second drainage pipe has one end connected to the portion of the first steam supply pipe located between the first steam valve and the first steam system.

4. The steam supply device for the steam-driven feedwater pump according to claim 1, characterized in that, The preset drainage pipe includes a first end and a second end. The first end is connected to the first steam supply pipe, and the second end extends out. One end of the preset pipe is connected to a preset position of the preset drainage pipe. A first valve is provided in the portion between the first end of the preset drainage pipe and the preset position.

5. The steam supply device for the steam-driven feedwater pump according to claim 1, characterized in that, The preset drainage pipe includes a first end and a second end. The first end is connected to the first steam supply pipe, and the second end extends out. One end of the preset pipe is connected to a preset position of the preset drainage pipe. A second valve is provided in the portion between the preset position and the second end of the preset drainage pipe.

6. The steam supply device for the steam-driven feedwater pump according to claim 1, characterized in that, A preset valve is installed on the preset pipeline.

7. The steam supply device for the steam-driven feedwater pump according to claim 1, characterized in that, A second steam valve is provided at one end of the second steam supply pipeline that is connected to the steam-driven feedwater pump; Also includes: The third drainage pipe is connected at one end to the portion of the second steam supply pipe located between the second steam valve and the steam-driven feedwater pump. Or / and a fourth drain pipe, one end of which is connected to the portion of the second steam supply pipe located between the second steam valve and the second steam system.

8. A water supply system for a thermal power generating unit, characterized in that, include: Steam-driven feedwater pump; A steam supply device for the steam-driven feedwater pump as described in any one of claims 1 to 7, connected to the steam-driven feedwater pump.

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