Water supply system with single water supply pump unit adapting to deep peak regulation

Abstract

The utility model belongs to the technical field of coal-fired power generation, and particularly relates to a water supply system with a single water supply pump unit adapting to deep peak regulation, which comprises a deaerator, a water outlet of the deaerator is connected with a water outlet pipeline, and the downstream of the water outlet pipeline is respectively connected with a boiler water supply pipeline and a circulating pipeline; the water outlet pipeline is sequentially connected with an inlet electrically operated gate, a steam pump booster pump and a steam feed pump from upstream to downstream; two groups of flow control modules are arranged on the circulating pipeline, the two groups of flow control modules are respectively arranged on the two circulating branches which are connected in parallel, and each flow control module comprises a flow valve front stop valve, a minimum flow valve and a flow valve rear stop valve; the output ends of the rear stop valves of the two groups of flow valves are connected with a water inlet of a check valve; a water outlet of the check valve is connected with a water inlet of a deaerator; the boiler water supply pipeline is connected with a boiler. The problems that after a traditional circulating system participates in peak regulation frequently, internal leakage is serious after a single valve is scoured continuously, and then output of a steam pump is seriously insufficient are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal-fired power generation, and in particular relates to a water supply system with a single water supply pump unit that is suitable for deep peak regulation. Background Art

[0002] In thermal power generation, the water output of the steam pump changes with the boiler load. When the load is low, the steam pump may face low water supply, causing the water temperature to rise to vaporization, which in turn causes cavitation and damages the steam pump. For this reason, a recirculation system is set up to reintroduce the water in the water supply container into the steam pump, increase the flow rate, reduce the water temperature, prevent vaporization and cavitation, and ensure the safe operation of the system.

[0003] At present, the patent with application number 202020384170.5 discloses a steam pump recirculation pipeline system, including a steam pump, a water supply container and a recirculation pipeline; the recirculation pipeline is provided with a recirculation valve and a first electric isolation valve; the first end of the steam pump is connected to the water outlet of the water supply container, and the second end of the steam pump is connected to the first end of the recirculation valve through the first electric isolation valve; the second end of the recirculation valve is connected to the water inlet of the water supply container.

[0004] Although the current system ensures that the water temperature is lowered through circulation at low loads, thereby reducing the risk of cavitation, the system needs to participate in peak regulation frequently. This causes a single valve in the circulation pipeline to leak after being continuously flushed, which in turn leads to serious insufficient output of the steam pump. Therefore, there is an urgent need for a water supply system that can adapt to deep peak regulation by reducing the flushing of a single valve during deep peak regulation and a single water supply pump unit. Utility Model Content

[0005] The utility model aims to provide a water supply system that can adapt to deep peak regulation by setting two sets of valves in the system to avoid the problem of internal leakage caused by flushing of a single valve and a single water supply pump unit.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A water supply system with a single water supply pump unit that is suitable for deep peak regulation comprises: a deaerator, wherein the water outlet of the deaerator is connected to a water outlet pipeline, and the downstream of the water outlet pipeline is respectively connected to a boiler water supply pipeline and a circulation pipeline; the water outlet pipeline is sequentially connected to an inlet electric door, a steam pump pre-pump and a steam-driven water supply pump from upstream to downstream; two groups of flow control modules are arranged on the circulation pipeline, and the two groups of flow control modules are respectively arranged on two parallel circulation branches, and the flow control modules include a flow valve front gate, a minimum flow valve and a flow valve rear gate, and the flow valve front gate, the minimum flow valve and the flow valve rear gate are sequentially arranged in the circulation branch from upstream to downstream; the output ends of the two groups of flow valve rear gates are connected to the water inlet of a check valve, and the water outlet of the check valve is connected to the water inlet of the deaerator; the boiler water supply pipeline is connected to the boiler.

[0008] Furthermore, a pre-pump filter is arranged between the inlet electric door and the steam pump pre-pump.

[0009] Furthermore, a flow meter and a pre-pump filter are arranged between the steam pump pre-pump and the steam-driven water supply pump, and the pre-pump filter is downstream of the flow meter.

[0010] Furthermore, the steam-driven feedwater pump is powered by a steam turbine.

[0011] Furthermore, a flow meter is arranged on the circulation pipeline, and a throttling orifice plate is arranged between the check valve and the deaerator.

[0012] Furthermore, the rated speed of the steam-driven water supply pump is 3000-5800rpm.

[0013] Compared with the prior art, the beneficial effects of the utility model are:

[0014] (1) The utility model is a water supply system based on a single water supply pump unit of a deaerator that is adapted to deep peak regulation. Specifically, the outlet of the deaerator is connected to the outlet pipeline, and the downstream of the outlet pipeline is respectively connected to the boiler water supply pipeline and the circulation pipeline. The former directly sends the water supply to the boiler, and the latter is provided by setting a parallel flow control module on the circulation pipeline. When the unit is under low load, part of the water supply is sent to the boiler, and the other part of the water is sent to the circulation pipeline. At this time, because flow control modules are provided on each parallel circulation branch, water passes through the flow valve front gate, the minimum flow valve and the flow valve rear gate on the two groups of flow control modules, so the flushing pressure of the single valve in the existing system is alleviated by diversion, thereby improving the deep peak regulation capability of the unit.

[0015] (2) The utility model effectively controls the flow, reduces pressure loss, improves system stability and equipment protection, and optimizes the deoxygenation effect by arranging a check valve on the pipeline and a throttling orifice plate between the deaerator, thereby improving the performance and operating efficiency of the overall system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] In the figure: 1. Deaerator; 2. Inlet electric door; 3. Pre-pump filter; 4. Steam pump pre-pump; 5. Flow meter; 6. Steam-driven feed water pump; 7. Steam turbine; 8. Stop gate before flow valve; 9. Minimum flow valve; 10. Stop gate after flow valve; 11. Check valve; 12. Throttle orifice; 20. Water outlet pipeline; 21. Boiler feed water pipeline; 22. Circulation pipeline. DETAILED DESCRIPTION

[0018] In order to make the technical means, creative features, purpose and efficacy of the utility model easy to understand, the utility model is further described below in conjunction with specific embodiments, but the following embodiments are only preferred embodiments of the utility model, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the utility model. The experimental methods in the following embodiments are all conventional methods unless otherwise specified, and the materials, reagents, etc. used in the following embodiments are all commercially available unless otherwise specified.

[0019] like Figure 1 In this embodiment, it includes: a deaerator 1, the water outlet of the deaerator 1 is connected to the water outlet pipeline 20, and the downstream of the water outlet pipeline 20 is respectively connected to the boiler feed water pipeline 21 and the circulation pipeline 22;

[0020] Specifically, when the unit is under normal load, the feed water is pressurized from the outlet water pipeline 20 and sent to the boiler feed water pipeline 21; when the unit is peak-shaving to low load, on the premise of meeting the feed water required by the boiler, the remaining feed water is sent to the circulation pipeline 22.

[0021] The water outlet pipeline 20 is connected to the inlet electric door 2, the steam pump pre-pump 4 and the steam-driven water supply pump 6 in sequence from upstream to downstream;

[0022] Specifically, the steam pump pre-pump 4 is used to increase the inlet pressure of the feed water and increase the flow rate to supply it to the steam-driven feed water pump 6, which is responsible for delivering the feed water to the boiler feed water pipeline 21 and the circulation pipeline 22;

[0023] Two groups of flow control modules are arranged on the circulation pipeline 22, and the two groups of flow control modules are arranged on two parallel circulation branches respectively. The flow control modules include a flow valve front gate 8, a minimum flow valve 9 and a flow valve rear gate 10, and the flow valve front gate 8, the minimum flow valve 9 and the flow valve rear gate 10 are arranged in sequence in the direction from upstream to downstream of the circulation branch;

[0024] Specifically, two branches are set up to alleviate the flushing pressure flow of only a single valve, wherein the valve front gate 8 mainly adjusts the switch state of the water supply according to the system demand or operation requirements, and controls the water supply to enter the downstream equipment or pipeline; the minimum flow valve 9 ensures that when the pipeline flow is lower than the set value, the minimum allowable flow can still be maintained; the flow valve 10 after the flow valve adjusts or closes the outflow of the water supply according to the needs, ensuring the normal operation and safety of the pipeline;

[0025] The output end of the two sets of flow valve rear gates 10 is connected to the water inlet of the check valve 11, and the water outlet of the check valve 11 is connected to the water inlet of the deaerator 1;

[0026] It should be noted that the check valve 11 ensures that the feed water can only flow from the water inlet of the check valve to the water outlet to prevent reverse flow. The water inlet of the deaerator 1 receives the feed water and performs deoxygenation treatment.

[0027] Specifically, when the stop valve 10 after the flow valve is opened, the feed water enters the water inlet of the check valve 11 from its output end; the check valve 11 ensures that the feed water can only flow from the water inlet to the water outlet to avoid backflow; the feed water flows out of the water outlet of the check valve 11 and is connected to the water inlet of the deaerator 1; in the deaerator 1, the feed water will be deoxygenated, and the treated feed water continues to flow into the next stage or equipment of the system.

[0028] The boiler feed water pipeline 21 is connected to the boiler.

[0029] It should be noted that the boiler is an existing device and will not be described in detail here.

[0030] In this embodiment, a pre-pump filter 3 is further arranged between the entrance electric door 2 and the steam pump pre-pump 4 .

[0031] In this embodiment, a flow meter 5 and a pre-pump filter 3 are further arranged between the steam pump pre-pump 4 and the steam-driven water supply pump 6 , and the pre-pump filter 3 is downstream of the flow meter 5 .

[0032] In this embodiment, the power of the steam-driven feedwater pump 6 comes from the steam turbine 7 .

[0033] In this embodiment, a flow meter 5 is provided on the circulation pipeline 22 , and a throttling orifice plate 12 is provided between the check valve 11 and the deaerator 1 .

[0034] It should be noted that the flow meter 5 is arranged upstream of the flow control module.

[0035] In this embodiment, the rated speed of the steam-driven water supply pump 6 is 3000-5800 rpm.

[0036] Working principle:

[0037] (1) When the unit is under normal load, the feed water is boosted from the outlet pipe 20 and sent to the boiler feed water pipe 21;

[0038] (2) When the unit is peak-shaving to low load, on the premise of meeting the feed water requirements of the boiler, the remaining feed water is sent to the circulation pipeline 22. At this time, the remaining feed water flows through the circulation pipeline 22 to the flow control module on its parallel circulation branch. At this time, the valve front gate 8 in the flow control module adjusts the switch state of the feed water according to the system requirements to control the feed water entering the downstream equipment or pipeline; the minimum flow valve 9 ensures that when the pipeline flow is lower than the set value, the minimum allowable flow rate can still be maintained; the flow valve rear gate 10 will adjust or close the outflow of feed water as needed to ensure the normal operation and safety of the pipeline. Finally, the two branches are connected to the check valve 11 to finally send the water back to the deaerator 1, and the feed water will be deoxygenated. The treated feed water continues to flow into the next stage or equipment of the system.

[0039] It should be noted that when the unit's deep peak regulation is to 30% or even below 30%, the two minimum flow valves are adjusted simultaneously to reduce the main feed water flow to meet the deep peak regulation of 30% capacity of the unit.

[0040] (3) When the minimum flow valve 9 of one of the groups leaks internally, the group with the current internal leak is reliably isolated for maintenance, while the other group operates normally, thus preventing part of the feed water from passing through the internal leaking valve into the recirculation pipeline, resulting in insufficient steam pump output, and greatly improving the reliability of the unit operation.

[0041] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the utility model and are not used to limit the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A water supply system with a single water supply pump unit adapted to deep peak regulation, comprising: The deaerator (1) is characterized in that the water outlet of the deaerator (1) is connected to a water outlet pipeline (20), and the downstream of the water outlet pipeline (20) is respectively connected to a boiler feed water pipeline (21) and a circulation pipeline (22); The water outlet pipeline (20) is connected to the inlet electric door (2), the steam pump pre-pump (4) and the steam-driven water supply pump (6) in sequence from upstream to downstream; Two groups of flow control modules are arranged on the circulation pipeline (22), and the two groups of flow control modules are respectively arranged on two parallel circulation branches, and the flow control modules include a flow valve front gate (8), a minimum flow valve (9) and a flow valve rear gate (10), and the flow valve front gate (8), the minimum flow valve (9) and the flow valve rear gate (10) are arranged in sequence in the direction from upstream to downstream of the circulation branch; The output ends of the two groups of flow valve rear stop valves (10) are connected to the water inlet of the check valve (11), and the water outlet of the check valve (11) is connected to the water inlet of the deaerator (1); The boiler feed water pipeline (21) is connected to the boiler.

2. The water supply system with a single water supply pump unit adapted to deep peak load regulation according to claim 1, characterized in that: A pre-pump filter (3) is also arranged between the inlet electric door (2) and the steam pump pre-pump (4).

3. The water supply system with a single water supply pump unit adapted to deep peak load regulation according to claim 2, characterized in that: A flow meter (5) and a pre-pump filter (3) are also arranged between the steam pump pre-pump (4) and the steam-driven water supply pump (6), and the pre-pump filter (3) is downstream of the flow meter (5).

4. The water supply system with a single water supply pump unit adapted to deep peak load regulation according to claim 1, characterized in that: The steam-driven water supply pump (6) is powered by a steam turbine (7).

5. The water supply system with a single water supply pump unit adapted to deep peak load regulation according to claim 1, characterized in that: A flow meter (5) is provided on the circulation pipeline (22), and a throttling orifice plate (12) is provided between the check valve (11) and the deaerator (1).

6. The water supply system with a single water supply pump unit adapted to deep peak load regulation according to claim 1, characterized in that: The rated speed of the steam-driven water supply pump (6) is 3000-5800 rpm.

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