LU504141B1 - Adjustment method for raise feed wat temperature under deep peak regulation working condition of coal-fired unit - Google Patents
Adjustment method for raise feed wat temperature under deep peak regulation working condition of coal-fired unit Download PDFInfo
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- LU504141B1 LU504141B1 LU504141A LU504141A LU504141B1 LU 504141 B1 LU504141 B1 LU 504141B1 LU 504141 A LU504141 A LU 504141A LU 504141 A LU504141 A LU 504141A LU 504141 B1 LU504141 B1 LU 504141B1
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- 238000000034 method Methods 0.000 title claims abstract description 27
- 230000033228 biological regulation Effects 0.000 title claims abstract description 22
- 230000001105 regulatory effect Effects 0.000 claims abstract description 51
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 26
- 238000000605 extraction Methods 0.000 claims description 59
- 238000005086 pumping Methods 0.000 claims description 20
- 239000011159 matrix material Substances 0.000 claims description 10
- 230000007423 decrease Effects 0.000 claims description 6
- 238000006073 displacement reaction Methods 0.000 claims description 5
- 230000002159 abnormal effect Effects 0.000 claims description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 10
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 5
- 229910021529 ammonia Inorganic materials 0.000 description 5
- 239000003546 flue gas Substances 0.000 description 5
- 230000008859 change Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 238000010977 unit operation Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- BIGPRXCJEDHCLP-UHFFFAOYSA-N ammonium bisulfate Chemical compound [NH4+].OS([O-])(=O)=O BIGPRXCJEDHCLP-UHFFFAOYSA-N 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000010531 catalytic reduction reaction Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D17/00—Regulating or controlling by varying flow
- F01D17/10—Final actuators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22D—PREHEATING, OR ACCUMULATING PREHEATED, FEED-WATER FOR STEAM GENERATION; FEED-WATER SUPPLY FOR STEAM GENERATION; CONTROLLING WATER LEVEL FOR STEAM GENERATION; AUXILIARY DEVICES FOR PROMOTING WATER CIRCULATION WITHIN STEAM BOILERS
- F22D1/00—Feed-water heaters, i.e. economisers or like preheaters
- F22D1/32—Feed-water heaters, i.e. economisers or like preheaters arranged to be heated by steam, e.g. bled from turbines
- F22D1/325—Schematic arrangements or control devices therefor
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Control Of Turbines (AREA)
Abstract
The invention relates to the technical field of deep peak-shaving control of a coal-fired unit, and discloses an adjusting method for improving the feed water temperature under the deep peak-shaving working condition of the coal-fired unit. When the coal-fired unit reaches the peak regulation standard, it enters the deep peak regulation mode to regulate the opening of the regulating valve of the intermediate pressure cylinder; And that deep peak regulation mode comprise the following step of: gradually regulating the opening of the intermediate pressure cylinder regulating valve to a preset intermediate pressure cylinder regulate valve opening value. The opening of the regulating valve of the intermediate pressure cylinder is regulated to improve the heat exchange quantity of the high-pressure heater and reduce the heat exchange loss of a tail flue economizer area under the deep peak regulation working condition.
Description
Adjustment method for raise feed wat temperature under deep peak “5944 regulation working condition of coal-fired unit
The invention relates to the technical field of deep peak-shaving control of a coal-fired unit, in particular to an adjusting method for increasing the feed water temperature under the deep peak-shaving working condition of the coal-fired unit.
Background technology
In recent years, the installed capacity of new energy power generation in China has been expanding, the traditional coal-fired power capacity is excessive, and the contradiction of peak shaving in power grid is very prominent. When the proportion of new energy in the power grid is gradually expanding, the demand for peak-shaving power supply is also gradually increasing.
Compared with new energy and other power sources, coal-fired power has better peak-shaving performance. In order to adapt to the new situation of power grid development, coal-fired power units need to tap the potential of peak regulation and improve the flexibility of unit operation.
At present, the selective catalytic reduction (SCR) technology is widely used in the denitration system of coal-fired power plants in China. The basic principle of this technology is to inject ammonia into the flue, mix it fully with the original flue gas and then enter the reaction tower. Under the action of catalyst, it selectively reacts with NOx in the flue gas to produce harmless ammonia and water. This technology is stable and reliable, but the reaction temperature is required to be controlled at 300 °C.- Between 450 °C. When the unit is under the deep peak load regulation condition, the heat load of the furnace is low, the flue gas temperature of the tail flue is low, which is often lower than the lower limit of the reaction required temperature, the denitration efficiency is low, the ammonia consumption is large, and the ammonia escape rate is too high, so it is easy to generate ammonium bisulfate and cause ash blockage in the air preheater.
In serious cases, it will lead to excessive environmental protection of the unit, or even unit shutdown.
At present, there are several methods to improve the feedwater temperature under the deep peak shaving condition: one is to add a No.0 HP heater to improve the feedwater temperature, which can improve the efficiency of the heater and reduce the heat rate of the turbine, but the ability of improving the feed-water temperature under deep peak shaving is limited (< 5 °C), and 904141 the cost of transformation is very high; The second is to transform the steam source of the heater.
Under the deep peak-shaving condition, the high-quality steam source is used to heat the feedwater. This method not only costs a lot, but also affects the operation of the steam turbine out of the design condition, which has a great impact on safety. Therefore, under the deep peak load regulation condition of the unit, it is of great significance to study a method to increase the main feedwater temperature and reduce the heat exchange loss in the tail flue economizer area, so as to improve the deep peak load regulation capacity of the unit and improve the safety margin of unit operation.
The invention provides an adjusting method for improving the feed water temperature under the deep peak regulation working condition of a coal-fired unit, which is characterized in that steam-water thermodynamic circulation of the coal-fired unit is not greatly changed, the opening of a regulating valve of an intermediate pressure cylinder is adjusted to improve the heat exchange quantity of a high-pressure heater under the deep peak regulation working condition, the heat exchange loss of a tail flue economizer area is reduced, and the feed water temperature is improved.
In order to realize the purpose, the invention provides the following scheme: the invention provides an adjusting method for improving the feed water temperature under the deep peak regulation working condition of a coal-fired unit, which comprises the following steps of:
Confirm whether the coal-fired unit has reached the peak shaving standard;
When the coal-fired unit reaches the peak regulation standard, it enters the deep peak regulation mode to regulate the opening of the regulating valve of the intermediate pressure cylinder;
The deep peak shaving mode comprises the following steps:
Presetting a regulating valve opening value of an intermediate pressure cylinder based on the pressure of a high-pressure cylinder steam exhaust pipeline;
Adjust the opening of the regulating valve of the intermediate pressure cylinder to the preset value of the opening of the regulating valve.
In one embodiment, the peak shaving criterion is:
The coal-fired unit is in a normal working state; LUS04141
The temperature in the first extraction conduit reaches a minimum temperature threshold for the first heater to heat feedwater, and the temperature in the second extraction conduit reaches a minimum temperature threshold for the second heater to heat feedwater.
In one embodiment, when the opening of the regulating valve of the intermediate pressure cylinder is adjusted to a preset opening value of the regulating valve of the intermediate pressure cylinder step by step, whether a plurality of parameter indexes are normal or not is detected, and when any parameter index is abnormal, the adjustment of the opening of the regulating door of the intermediate voltage cylinder is stopped and an alarm is given.
In one embodiment, the parameter indicators include axial displacement, bearing Bush vibration, thrust pad temperature, reheater pressure, pumping pressure, intermediate pressure cylinder exhaust steam temperature, low pressure cylinder stationary blade carrier ring, and low pressure cylinder exhaust steam temperature.
In one embodiment, the presetting the opening value of the governing valve of the IP cylinder based on the pressure of the exhaust steam pipe of the HP cylinder comprises:
Detecting the pressure P of the exhaust pipe of the high-pressure cylinder in real time;
The opening value G of the intermediate pressure cylinder regulating valve is set based on the relationship between the pressure P and each preset pressure.
In one embodiment, a preset pressure matrix PO is preset, and PO = (P1, P2, P3, P4) is set, where P1 is a first preset pressure, P2 is a second preset pressure, P3 is a third preset pressure and P4 is a fourth preset pressure, and P1 < P2 <P3 <P4;
Presetting a preset opening value matrix GO, and setting GO = (G1, G2, G3, G4), wherein
Gl is a first preset opening value, G2 is a second preset opening value, G3 is a third preset open value, G4 is a fourth preset open value, and G1 < G2 < G3 < G4;
An opening value G is set according to the relationship between the pressure P and each preset pressure:
When P <P1, the first preset opening value G1 is selected as the opening value G;
When P1 = P <P2, the second preset opening value G2 is selected as the opening value G;
When P2 = P <P3, the third preset opening value G3 is selected as the opening value G;
When P3 = P <P4, the fourth preset opening value G4 is selected as the opening value G.
In one embodiment, the step of adjusting the opening of the intermediate pressure cylinder regulating valve to the preset value of the opening of the intermediate pressure cylinder 904141 regulating valve comprises:
The open of that intermediate pressure cylinder regulating valve is adjust to a preset intermediate pressure cylinder regulating valve opening value step by step within a preset adjusting time;
The open value of that preset intermediate pressure cylinder regulating valve is in the range of 0.5 to 3% of the open of the regulating valve; The preset adjustment time is 30-60s; Adjust the valve opening by 0.1-0.2% at each step.
In one embodiment, the deep peak shaving mode further comprises: the first air extraction assembly and the second air extraction assembly operate normally alternately;
The first air extraction assembly comprises a first air extraction pipeline which is provided with a first electromagnetic valve;
And that second air pump assembly comprises a second air pump pipeline on which a second electromagnetic valve is arranged.
In one embodiment, the first air extraction assembly and the second air extraction assembly operate normally alternately, comprising:
Respectively determining a first pressure value when the temperature of the feedwater heated by the first heater reaches a first minimum temperature threshold and a second pressure value when the temperature of the feedwater heated by the second heater reaches a second minimum temperature threshold,
Determining a lowest opening threshold of a first solenoid valve on a first extraction pipeline and a second opening threshold of a second solenoid valve on a second extraction pipeline based on the first pressure value and the second pressure value;
Detecting a first pumping pressure of the first pumping pipeline and a second pumping pressure of the second pumping pipeline in real time;
An opening degree of the first solenoid valve and an opening degree of the second solenoid valve are adjusted based on a relationship between the first suction pressure and the first pressure value and a relationship between the second suction pressure and the second pressure value.
In one embodiment, adjusting an opening degree of the first solenoid valve and an opening degree of the second solenoid valve based on a relationship between the first suction pressure and the first pressure value and a relationship between the second suction pressure and the 904141 second pressure value comprises:
In that first preset time, the first electromagnetic valve on the first air extraction pipeline is kept at the first low opening threshold; A second electromagnetic valve on a second air extraction 5 pipeline is kept at a normal open degree; The first preset time is based on the time for the temperature of the feedwater heated by the first heater to decrease from an initial temperature to a first minimum temperature threshold;
In that second preset time, the second electromagnetic valve on the second air extraction pipeline is kept at the second low opening threshold; Nable that first electromagnetic valve on the first air extraction pipeline to keep normal opening; The second preset time is based on a time for the temperature of the feedwater heated by the second heater to decrease from the initial temperature to a second minimum temperature threshold.
The method has the technical effects that the opening of the regulating valve of the intermediate-pressure cylinder is adjusted by entering a deep peak regulation mode after a coal-fired unit reaches a peak regulation standard, and the accuracy of the preset opening value of the regulating valve of the intermediate-pressure cylinder is improved by presetting the opening value of the regulating door of the intermediate-voltage cylinder based on the pressure of an exhaust steam pipeline of a high-pressure cylinder; Adjust the opening of the governing valve of the intermediate pressure cylinder to the preset opening value of the governing valve of the intermediate pressure cylinder step by step, so as to avoid sudden pressure change of the first extraction steam pipe and the exhaust steam pipe of the high pressure cylinder caused by sudden adjustment of the opening of the regulating valve.
Description of attached figures
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, Other figures may also be derived from these figures.
Brief description of the drawings fig. 1 is a schematic diagram of an adjustment method for increasing the feed water temperature of a coal-fired unit under a deep peak-shaving condition according to an embodiment of the present invention; LUS04141
FIG. 2 is a schematic diagram of a position adjusting device according to an embodiment of the present invention;
Fig. 3 is a schematic diagram of a rainwater collection and treatment device according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a drying device according to an embodiment of the present invention;
Fig. 5 is a flow chart of a method for cleaning a nacelle of a wind turbine according to an embodiment of the present invention.
Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples illustrate the invention but are not intended to limit the scope of the invention.
In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", and "rear", left "and" right ", vertical" and "horizontal", top "and bottom", inner "and outer" is based on the orientation or positional relationship shown in the drawings, which is only for convenience of description of the present application and simplification of description. It is not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the application.
The terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or as implying the number of technical features indicated. Thus, the features defined as "first" or "second" may be explicitly or implicitly defined as including one or more of the features. In the description of the present application, "a plurality" means two or more unless otherwise specified.
In the description of the present application, it should be noted that the terms "mounted", "connected", and "connected" are to be construed broadly, unless otherwise specifically defined and limited, and may be, for example, fixedly connected, removably connected, or integrally connected; Can be mechanically connecte or electrically connected; It can be directly connected or indirectly connected through an intermediate medium, and it can be the internal 20 + communication of two components. Those of ordinary skill in the art can understand the specific meaning of the above terms in the present application in a specific context.
As shown in fig. 2, the existing main steam 1 enters a high-pressure cylinder 4 to do work through a high-pressure main steam valve 2 and a high-pressure regulating valve 3, the steam which has done work in the middle stage part enters a first high-pressure heater to heat feed water through a first middle steam extraction pipeline 8, and the rest steam enters a high-pressure cylinder steam exhaust pipeline 6 through a high-pressure cylinder steam exhaust check valve 5 and is sent to a reheater to be heated. Wherein a part of the high pressure exhaust steam enters the second high pressure heater through the second steam extraction pipeline 7 to heat the feed water. The reheated steam 9 heated by the reheater enters the intermediate pressure cylinder 12 to do work through the intermediate pressure main throttle valve 10 and the intermediate pressure cylinder regulating valve 11.
After the governing valves 11 and 13 of the intermediate pressure cylinder are turned down, the throttling effect of the reheated steam passing through the governing valves of the intermediate pressure cylinder will increase the steam pressure in front of the governing valve, and the pressure of the exhaust steam pipe 6 and the first extraction steam pipe 8 of the high pressure cylinder will increase correspondingly. Under the same heat load, the steam entering the first and second heaters will have higher pressure, larger flow, stronger working capacity and higher temperature rise of water supply. Thereby reducing the heat exchange quantity of the economizer area, improving the flue gas temperature before the SCR, ensuring the working efficiency of the denitration device, and avoiding unsafe events such as environmental protection exceeding standard, air preheater blockage and the like.
The improvement of the prior art is that a first electromagnetic valve is arranged on a first air extraction pipeline, and a second electromagnetic valve is arranged on a second air extraction pipeline; Install the detection device to confirm the axial displacement, bearing Bush vibration, thrust pad temperature, reheater pressure, extraction pressure, IP cylinder exhaust temperature,
LP cylinder stationary blade carrier ring, LP cylinder exhaust temperature and other parameters.
As shown in figs. 1-3, this embodiment discloses an adjustment method for increasing the feed water temperature under the deep peak-shaving condition of a coal-fired unit, which
. LU504141 comprises:
Step S001,determining whether the coal-fired unit reaches the peak shaving standard ;
Step S002,when the coal-fired unit reaches the peak shaving standard, it enters the deep peak shaving mode to adjust the opening of the regulating valve of the intermediate pressure cylinder ;
The deep peak shaving mode includes:
Tep S10, presetting an opening value of a regulating valve of an intermediate pressure cylinder based on the pressure of a steam exhaust pipeline of the high pressure cylinder;
And step S20, adjust that opening of the regulate valve of the intermediate pressure cylinder to a preset opening value of the regulating valve of the intermediate pressure cylinder step by step.
It can be understood that, in the above embodiment, the opening of the intermediate pressure cylinder governing valve is adjusted by entering the deep peak shaving mode after the coal-fired unit reaches the peak shaving standard, and the accuracy of the preset opening value of the intermediate pressure cylinder governing valve is improved by presetting the opening value based on the pressure of the high pressure cylinder exhaust steam pipeline; The opening of the governing valve of the intermediate pressure cylinder is adjusted to the preset opening value of the governing valve of the intermediate pressure cylinder step by step, so as to avoid sudden pressure change of the first extraction pipe and the exhaust pipe of the high pressure cylinder caused by directly adjusting the opening of the regulating valve.
In some embodiments, the peak shaving criteria are that the coal-fired unit is in normal operation;
The temperature in the first extraction conduit reaches a minimum temperature threshold for the first heater to heat feedwater, and the temperature in the second extraction conduit reaches a minimum temperature threshold for the second heater to heat feedwater.
It can be understood that, in the above embodiment, after the coal-fired unit is in a normal working state, the first heater and the second heater can be stably heated for deep peak shaving, so as to avoid failure of subsequent deep peak shaving.
In some specific embodiments, when the opening of the regulating valve of the intermediate pressure cylinder is regulated to a preset opening value of the regulating valve of the intermediate pressure cylinder step by step, whether a plurality of parameter indexes are 904141 normal or not is detected, and when any parameter index is abnormal, the adjustment of the opening of the governing valve is stopped and an alarm is given.
Parameter indexes include axial displacement, bearing Bush vibration, thrust pad temperature, reheater pressure, extraction pressure, IP cylinder exhaust steam temperature, LP cylinder stationary blade carrier and LP cylinder exhaust steam temperature.
It can be understood that in the above embodiment, the normal parameter indexes are as follows: the axial displacement is within the range of -0.5mm to + 0.5mm, the bearing pad vibration is less than or equal to 9.3mm/s, the thrust pad temperature is less than or equal to 120.d egree. Secondary extraction pressure = 6.08 MPa, steam exhaust temperature of IP casing = 295 °C, stationary blade carrier of LP casing = 180 °C or steam exhaust temperature of LP casing = 90 °C.
It should be noted that the above normal parameter indexes can be other range values selected by those skilled in the art according to the actual situation of the specific coal-fired unit, which does not affect the scope of protection of the present application.
As shown in fig. 4, in some embodiments, in step S10, the opening value of the intermediate pressure cylinder governing valve is preset based on the pressure of the exhaust steam pipe of the high pressure cylinder, including:
S11, detecting the pressure P of the steam exhaust pipeline of the high-pressure cylinder in real time;
In step S12, the opening value G of the intermediate pressure cylinder regulating valve is set based on the relationship between the pressure P and each preset pressure.
Preferably, a preset pressure matrix PO is preset, and PO = (P1, P2, P3, P4) is set, wherein
P1 is a first preset pressure, P2 is a second preset pressure, P3 is a third preset pressure and P4 is a fourth preset pressure, and P1 < P2 < P3 <P4;
Presetting a preset opening value matrix GO, and setting GO = (G1, G2, G3, G4), wherein
Gl is a first preset opening value, G2 is a second preset opening value, G3 is a third preset open value, G4 is a fourth preset open value, and G1 < G2 < G3 < G4;
The opening value G is set according to the relationship between the pressure P and each preset pressure:
When P <P1, the first preset opening value G1 is selected as the opening value G;
When P1 = P <P2, the second preset opening value G2 is selected as the opening value G-V504141
When P2 = P <P3, the third preset opening value G3 is selected as the opening value G;
When P3 = P <P4, the fourth preset open value G4 is selected as the open value G.
It can be understood that, in the above embodiment, the opening value G is set according to the relationship between the pressure P and each preset pressure, so as to improve the accuracy of setting the opening value G, and avoid sudden change of the pressure of the first extraction steam pipeline and the exhaust steam pipeline of the high pressure cylinder due to error in adjusting the opening of the governing valve of the intermediate pressure cylinder, or too low heating temperature of the first high pressure heater and the second high pressure heater.
Specifically, it is assumed that the pressure P of the exhaust steam pipe of the high pressure cylinder is in the range of 6-8 MPa, and the adjustment range of the opening value Gis 1% -3%.
A preset pressure matrix PO is preset, and PO = (6.5 MPA, 7 MPA, 7.5 MPA, 8 MPA) is set, wherein 6.5 MPA is a first preset pressure, 7 MPA is a second preset pressure, 7.5 MPA is a third preset pressure and 8 MPa is a fourth preset pressure. 6.0MP < 6.5MPA < 7MPA < 7.5MPA < 8MPA;
Presetting a preset opening value matrix GO, and setting GO = (99%, 98.5%, 98%, 97.5%), wherein 99% is a first preset opening value, 98.5% is a second preset opening value, 98% is a third preset open value, and 97.5% is the fourth preset open value, and 99% < 98.5% < 98% < 97.5;
The opening value G is set according to the relationship between the pressure P and each preset pressure:
When P is less than 6.5 MPA, the first preset opening value 99% is selected as the opening value G;
When 6.5 MPa = P <7 MPA, the second preset opening value 98.5% is selected as the opening value G;
When 7 MPa = P < 7.5 MPA, the third preset opening value 98% is selected as the opening value G;
When 7.5 MPA ltoreq.P.ltoreq.8 MPA, the fourth preset opening value 97.5% is selected as the opening value G.
It should be noted that the solution of the above preferred embodiment is only a specific implementation mode proposed by the present application, and a person skilled in the art may select other preset pressure matrix PO and preset opening value matrix GO according to the actual 04 4 situation, which does not affect the scope of protection of the present application.
In some embodiments, in step S20, the step of adjusting the opening of the intermediate pressure cylinder valve to the preset value of the opening of the intermediate pressure cylinder valve comprises:
The open of that intermediate pressure cylinder regulating valve is adjust to a preset intermediate pressure cylinder regulating valve opening value step by step within a preset adjusting time;
The opening value of the regulating valve of the intermediate pressure cylinder is preset to be within the range of 0.5% -3% of the opening of the regulating valve; The preset adjustment time is 30-6.50S; Adjust the valve opening by 0.1-0.2% at each step.
It can be understood that, in the above embodiment, in order to prevent sudden change of the pressure of the first steam extraction pipeline and the steam exhaust pipeline of the high pressure cylinder caused by sudden adjustment of the opening of the governing valve of the intermediate pressure cylinder, the opening of the governing valve of the intermediate pressure cylinder is gradually adjusted to the preset value within the preset adjustment time.
It should be noted that the preset opening value of the governing valve of the intermediate pressure cylinder is within the range of 0.5% -3% of the opening of the governing valve; The preset adjustment time is 30-6.50S; If the opening of the regulating valve is lowered by 0.1-0.2% in each step, other range values can be selected by those skilled in the art according to the specific coal-fired unit and the actual situation, which does not affect the scope of protection of the present application.
In some specific embodiments, the deep peak shaving mode further comprises a step S30 of alternately and normally operating the first air extraction assembly and the second air extraction assembly;
The first air extraction component comprises a first air extraction pipeline which is provided with a first electromagnetic valve;
The second air pumping assembly comprises a second air pumping pipeline, and a second electromagnetic valve is arranged on the second air pumping pipeline.
It can be understood that, in the above embodiment, part of the energy of the steam-water thermodynamic cycle of the coal-fired unit is transferred in time and space by alternately and 904141 normally operating the first air extraction assembly and the second air extraction assembly, so as to improve the efficiency of the heater and reduce the heat consumption rate of the steam turbine.
As shown in fig. 5, in some embodiments, in step S30, the first air extraction assembly and the second air extraction assembly operate normally alternately, including:
S31, respectively determining a first pressure value when the temperature of the feed water heated by the first heater reaches a first minimum temperature threshold and a second pressure value when the temperature of the feed water heated by the second heater reaches a second minimum temperature threshold,
S32, determining the lowest opening threshold of the first solenoid valve on the first extraction pipeline and the second opening threshold of the second solenoid valve on the second extraction pipeline based on the first pressure value and the second pressure value;
S33, detecting a first pumping pressure of the first pumping pipeline and a second pumping pressure of the second pumping pipeline in real time;
In step S34, the opening degree of the first solenoid valve and the opening degree of the second solenoid valve are adjusted based on the relationship between the first pumping pressure and the first pressure value and the relationship between the second pumping pressure and the second pressure value.
Specifically, in step S34, adjusting the opening degree of the first solenoid valve and the opening degree of the second solenoid valve based on the relationship between the first pumping pressure and the first pressure value and the relationship between the second pumping pressure and the second pressure value includes:
In step S341, the first solenoid valve on the first extraction pipeline is kept at the first minimum opening threshold within the first preset time. A second electromagnetic valve on a second air extraction pipeline is kept at a normal open degree; The first preset time is based on the time when the temperature of the feedwater heated by the first heater decreases from an initial temperature to a first minimum temperature threshold,
S342, in a second preset time, that second solenoid valve on the second air extraction pipeline is kept at a second minimum open threshold; Nable that first electromagnetic valve on the first air extraction pipeline to keep normal opening; The second preset time is based on the time when the temperature of the feedwater heated by the second heater decreases from the 204141 initial temperature to a second minimum temperature threshold.
It can be understood that, in the above embodiment, by adjusting the opening of the first solenoid valve and the opening of the second solenoid valve within the preset time, the first air extraction assembly and the second air extraction assembly are alternately and normally operated, and the heat consumption rate of the turbine is reduced on the basis of meeting the requirement of normal heating and water supply.
The adjusting method for improving the feed water temperature under the deep peak regulation working condition of the coal-fired unit provided by the invention has the advantages that: 1, only the operation mode of the existing equipment needs to be adjusted, no new equipment or technical transformation is needed, and the cost is saved. 2. The operation method is simple, and can realize one-key automatic operation in the whole process, automatically limit the valve limit and check the relevant parameters in the whole process, avoid personnel misoperation, and ensure the normal operation of the main parameters of the unit. 3. Under the condition of deep peak regulation, the heat exchange capacity of the HP heater is increased by gradually turning down the regulating valve of the IP cylinder to increase the feed water temperature, which can effectively increase the flue gas temperature at the inlet before SCR, avoid the unit exceeding the environmental protection standard or the air preheater being blocked, and improve the safety margin of the unit. At the same time, it can reduce the use of ammonia and improve the economy under deep peak shaving conditions.
It should be understood that although the steps in the flowchart of the various embodiments of the present invention are shown sequentially as indicated by the arrows, the steps are not necessarily performed sequentially in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order in which the steps may be performed, and the steps may be performed in other orders. Moreover, at least a part of the steps in each embodiment may include a plurality of sub-steps or phases, and these sub-steps or phases are not necessarily executed at the same time, but may be executed at different times, and the execution order of these sub-steps and phases is not necessarily sequential. But may be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.
Those of ordinary skill in the art can understand that the above is only a preferred. 204141 embodiment of the present invention, and is not intended to limit the present invention.
Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions to some of the technical features.
Any modification, equivalent substitution, improvement, etc.
Within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims (10)
- CLAIMS LU504141 l.An adjustment method for increasing the feed water temperature under the deep peak-shaving condition of a coal-fired unit, comprising; confirm whether the coal-fired unit has reached the peak shaving standard, when the coal-fired unit reaches the peak regulation standard, it enters the deep peak regulation mode to regulate the opening of the regulating valve of the intermediate pressure cylinder; the deep peak shaving mode comprises the following steps: presetting a regulating valve opening value of an intermediate pressure cylinder based on the pressure of a high-pressure cylinder steam exhaust pipeline; adjust the opening of the regulating valve of the intermediate pressure cylinder to the preset value of the opening of the regulating valve.
- 2. The adjustment method for increasing the feedwater temperature under the deep peak shaving working condition of the coal-fired unit according to claim 1, wherein the peak shaving standard is as follows: the coal-fired unit is in a normal working state; the temperature in the first extraction conduit reaches a minimum temperature threshold for the first heater to heat feedwater, and the temperature in the second extraction conduit reaches a minimum temperature threshold for the second heater to heat feedwater.
- 3. The adjustment method for increasing the feed water temperature under the deep peak regulation working condition of the coal-fired unit according to claim 1, which is characterized in that when the opening of the regulating valve of the intermediate pressure cylinder is adjusted to a preset opening value of the regulating valve of the intermediate pressure cylinder step by step, whether a plurality of parameter indexes are normal or not is detected, and when any parameter index is abnormal, the adjustment of the opening of the governing valve of an intermediate pressure cylinder is stopped and an alarm is given. 4 The adjustment method for increasing the feed water temperature of a coal-fired unit under a deep peak shaving condition according to claim 3, wherein the parameter indexes comprise axial displacement, bearing Bush vibration, thrust pad temperature, reheater pressure,
- extraction pressure, intermediate pressure cylinder exhaust steam temperature, low pressure. 904141 cylinder stationary blade carrier ring and low pressure cylinder exhaust steam temperature.
- 5. The adjustment method for increasing the feed water temperature under the deep peak shaving working condition of the coal-fired unit according to claim 1, wherein the presetting the opening value of the governing valve of the IP cylinder based on the pressure of the exhaust steam pipe of the HP cylinder comprises: detecting the pressure P of the exhaust pipe of the high-pressure cylinder in real time; the opening value G of the intermediate pressure cylinder regulating valve is set based on the relationship between the pressure P and each preset pressure.
- 6. The adjustment method for increasing the feedwater temperature under the deep peak-shaving condition of a coal-fired unit according to claim 5, wherein presetting a predetermined pressure matrix PO and setting PO = (P1, P2, P3, P4), wherein P1 is a first predetermined pressure, P2 is a second predetermined pressure, P3 is a third predetermined pressure and P4 is a fourth predetermined pressure; P1 <P2 <P3 <P4; presetting a preset opening value matrix GO, and setting GO = (G1, G2, G3, G4), wherein Gl is a first preset opening value, G2 is a second preset opening value, G3 is a third preset open value, G4 is a fourth preset open value, and G1 < G2 < G3 < G4; an opening value G is set according to the relationship between the pressure P and each preset pressure: when P <P1, the first preset opening value G1 is selected as the opening value G; when P1 = P <P2, the second preset opening value G2 is selected as the opening value G; when P2 = P< P3, the third preset opening value G3 is selected as the opening value G; when P3 = P <P4, the fourth preset opening value G4 is selected as the opening value G.
- 7. The adjustment method for increasing the feed water temperature under the deep peak shaving working condition of the coal-fired unit according to claim 1, wherein the adjusting the opening of the intermediate pressure cylinder governing valve to the preset intermediate pressure cylinder governing valve opening value step by step comprises: the open of that intermediate pressure cylinder regulating valve is adjust to a preset intermediate pressure cylinder regulating valve opening value step by step within a preset adjusting time; the open value of that preset intermediate pressure cylinder regulating valve is in the range of 0.5 to 3% of the open of the regulating valve; The preset adjustment time is 30-60s; Adjust the 904141 valve opening by 0.1-0.2% at each step.
- 8. The adjustment method for increasing the feed water temperature under the deep peak shaving working condition of the coal-fired unit according to claim 1, wherein the deep peak shaving mode further comprises: the first air extraction assembly and the second air extraction assembly operate normally alternately; the first air extraction assembly comprises a first air extraction pipeline which is provided with a first electromagnetic valve; and that second air pump assembly comprises a second air pump pipeline on which a second electromagnetic valve is arranged.
- 9. The adjustment method for increasing the feed water temperature under the deep peak shaving working condition of a coal-fired unit according to claim 8, wherein the first air extraction assembly and the second air extraction assembly operate normally alternately, comprising: respectively determining a first pressure value when the temperature of the feedwater heated by the first heater reaches a first minimum temperature threshold and a second pressure value when the temperature of the feedwater heated by the second heater reaches a second minimum temperature threshold, determining a lowest opening threshold of a first solenoid valve on a first extraction pipeline and a second opening threshold of a second solenoid valve on a second extraction pipeline based on the first pressure value and the second pressure value; detecting a first pumping pressure of the first pumping pipeline and a second pumping pressure of the second pumping pipeline in real time; an opening degree of the first solenoid valve and an opening degree of the second solenoid valve are adjusted based on a relationship between the first suction pressure and the first pressure value and a relationship between the second suction pressure and the second pressure value.
- 10. The method of claim 9, wherein adjusting the opening of the first solenoid valve and the opening of the second solenoid valve based on the relationship between the first suction pressure and the first pressure value and the relationship between the second suction pressure and the second pressure value comprises:in that first preset time, the first electromagnetic valve on the first air extraction pipeline TS 904141 kept at the first low opening threshold; A second electromagnetic valve on a second air extraction pipeline is kept at a normal open degree; The first preset time is based on the time for the temperature of the feedwater heated by the first heater to decrease from an initial temperature to a first minimum temperature threshold;in that second preset time, the second electromagnetic valve on the second air extraction pipeline is kept at the second low opening threshold; Nable that first electromagnetic valve on the first air extraction pipeline to keep normal opening; The second preset time is based on a time for the temperature of the feedwater heated by the second heater to decrease from the initial temperature to a second minimum temperature threshold.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211567398.8A CN116163812A (en) | 2022-12-07 | 2022-12-07 | Adjusting method for improving water supply temperature under deep peak regulation working condition of coal-fired unit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| LU504141B1 true LU504141B1 (en) | 2023-11-06 |
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ID=86412136
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| LU504141A LU504141B1 (en) | 2022-12-07 | 2023-05-06 | Adjustment method for raise feed wat temperature under deep peak regulation working condition of coal-fired unit |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN116163812A (en) |
| LU (1) | LU504141B1 (en) |
-
2022
- 2022-12-07 CN CN202211567398.8A patent/CN116163812A/en active Pending
-
2023
- 2023-05-06 LU LU504141A patent/LU504141B1/en active IP Right Grant
Also Published As
| Publication number | Publication date |
|---|---|
| CN116163812A (en) | 2023-05-26 |
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| FG | Patent granted |
Effective date: 20231106 |