CN114837810A - Method and system for controlling and improving efficiency of wide-load operation of gas-steam combined cycle peak shaving unit - Google Patents
Method and system for controlling and improving efficiency of wide-load operation of gas-steam combined cycle peak shaving unit Download PDFInfo
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- 239000002918 waste heat Substances 0.000 claims abstract description 40
- 239000000463 material Substances 0.000 claims abstract description 28
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- 239000003546 flue gas Substances 0.000 claims abstract description 4
- 238000009991 scouring Methods 0.000 claims abstract description 4
- 230000001276 controlling effect Effects 0.000 claims description 46
- 230000008859 change Effects 0.000 claims description 31
- 238000002485 combustion reaction Methods 0.000 claims description 27
- 230000009467 reduction Effects 0.000 claims description 21
- 238000003303 reheating Methods 0.000 claims description 18
- 238000005457 optimization Methods 0.000 claims description 7
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C6/00—Plural gas-turbine plants; Combinations of gas-turbine plants with other apparatus; Adaptations of gas-turbine plants for special use
- F02C6/18—Plural gas-turbine plants; Combinations of gas-turbine plants with other apparatus; Adaptations of gas-turbine plants for special use using the waste heat of gas-turbine plants outside the plants themselves, e.g. gas-turbine power heat plants
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C6/00—Plural gas-turbine plants; Combinations of gas-turbine plants with other apparatus; Adaptations of gas-turbine plants for special use
- F02C6/14—Gas-turbine plants having means for storing energy, e.g. for meeting peak loads
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C9/00—Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B33/00—Steam-generation plants, e.g. comprising steam boilers of different types in mutual association
- F22B33/18—Combinations of steam boilers with other apparatus
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22G—SUPERHEATING OF STEAM
- F22G3/00—Steam superheaters characterised by constructional features; Details of component parts thereof
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22G—SUPERHEATING OF STEAM
- F22G5/00—Controlling superheat temperature
- F22G5/12—Controlling superheat temperature by attemperating the superheated steam, e.g. by injected water sprays
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E20/00—Combustion technologies with mitigation potential
- Y02E20/16—Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]
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Abstract
The invention discloses a method and a system for controlling and improving efficiency of a fuel gas and steam combined cycle peak shaving unit in wide load operation, wherein the method comprises the following steps: arranging a final-stage reheater on the first-stage heating surface, wherein the final-stage reheater is closest to the outlet of the gas turbine and directly bears the scouring of high-temperature flue gas; upgrading the material of a final-stage reheater of the waste heat boiler to adapt to higher outlet steam temperature of the waste heat boiler; the desuperheating water of the high-pressure superheater is extracted from the outlet of the high-pressure feed water pump and is extracted from the interstage of the high-pressure economizer, so that the outlet parameters of high-pressure main steam are improved; operating the gas-steam combined cycle unit by utilizing the air with the temperature raised; the invention utilizes the characteristic that the gas turbine has higher exhaust gas temperature at partial load, can improve the steam parameters at the outlet of the waste heat boiler (equivalent to improving the initial parameters at the inlet of the steam turbine) by adjusting the arrangement of the heating surface of the waste heat boiler, is favorable for improving the efficiency of a unit, and can obtain larger system efficiency improvement by improving the temperature of reheat steam than the temperature of high-pressure main steam.
Description
Technical Field
The invention relates to the technical field of power generation of a gas-steam combined cycle unit, in particular to a method and a system for controlling and improving efficiency of a gas-steam combined cycle peak shaving unit in wide-load operation.
Background
The natural gas peak regulation power station has the characteristics that the natural gas peak regulation power station only runs with partial load in most time, and the annual utilization hours of the unit is low. In order to make the peak shaving power station have higher benefit, the efficiency of the main engine is obviously required to be improved, and the efficiency is under the working condition of partial load. Some host manufacturers at present propose some improved schemes, such as air compressor intake heating, that is, using low-grade hot water of a waste heat boiler, injecting the hot water into an intake chamber of an intake system to install a heat exchange coil for heating air, heating the temperature of the air entering the air compressor through heat exchange with the intake air, mixing the hot water from a low-pressure economizer and condensed water from a condenser according to a certain proportion to reach the required temperature and flow, entering a coil heat exchanger, performing air heat exchange to increase the air temperature, and returning the outlet water to the condensed water. The temperature and the pressure of hot water from a low-pressure economizer, condensed water from a condenser, mixed coil inlet water and coil outlet water are monitored, and the inlet water flow is controlled through the temperature end difference of the water side, so that the following defects exist in the technology:
1. an additional heat exchanger (a coil heat exchanger), a water pump and the like are required to realize water side circulation, so that initial investment is increased, and resistance of an air inlet system is increased;
2. the heat exchange amount of the low-pressure economizer is increased, the heat exchange area of the low-pressure economizer is also increased, and the initial investment of the waste heat boiler body is increased;
3. in order to control the flow of condensed water and hot water of the low-pressure economizer, two sets of regulating valve banks are required to be arranged on two systems respectively, so that the initial investment is increased, the system control is complex, and the reliability is reduced;
4. with the increase of the inlet air temperature, the amount of heat extracted from the low-pressure smoke-saving device is increased, and the exhaust temperature of the waste heat boiler is gradually lowered. Considering the safety of the heating surface at the tail part of the boiler, the inlet air temperature is not suitable for being heated too high, so the yield of efficiency improvement by adopting the method is very little;
5. the adaptation scope is little, and the unit load is lower, and the promotion of the back efficiency of heating of admitting air and putting into operation is obvious consequently, and prior art has the defect, needs the improvement.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a method and a system for controlling and improving the effect of a fuel gas and steam combined cycle peak shaving unit in the wide-load operation, so as to solve the problems in the background technology. In order to achieve the purpose, the invention adopts the following technical scheme: the method and the system for controlling and improving the effect of the wide-load operation of the gas-steam combined cycle peak shaving unit comprise the following steps:
acquiring an actual power value and a target power value of the gas-steam combined cycle unit;
raising the temperature of air entering an air inlet of an air inlet module of the gas-steam combined cycle unit;
controlling the load of the gas turbine according to the deviation of the actual power value and the target load value, so that the actual power value is consistent with the target load value;
arranging a final-stage reheater on the first-stage heating surface, wherein the final-stage reheater is closest to the outlet of the gas turbine and directly bears the scouring of high-temperature flue gas;
upgrading the material of a final-stage reheater of the waste heat boiler to adapt to higher outlet steam temperature of the waste heat boiler;
the desuperheating water of the high-pressure superheater is extracted from the outlet of the high-pressure feed water pump and is extracted from the interstage of the high-pressure economizer, so that the outlet parameters of high-pressure main steam are improved;
and operating the gas-steam combined cycle unit by utilizing the air with the temperature raised.
Preferably, the method further comprises:
correcting the load proportion of the gas turbine and the waste heat boiler-steam turbine according to the actual operation condition of the gas-steam combined cycle unit;
and automatically calculating the load change rate of the gas-steam combined cycle unit according to the upper limit and the lower limit of the load change rate of the gas turbine, the exhaust temperature and the steam turbine cylinder temperature change rate, and controlling the synchronous load increase of the gas turbine and the steam turbine according to the load change rate.
Preferably, the method further comprises:
the method comprises the steps of controlling the sequential control start and stop with breakpoint confirmation under the working conditions of cold start, warm start, hot start and normal stop of the steam turbine, and controlling the load-lifting rate of the gas turbine under the working conditions of diffusion combustion, mixed combustion and premixed combustion.
Preferably, the method further comprises: and calculating the maximum load capacity values which can be borne by the gas-steam combined cycle unit under different operating conditions, and enabling the gas-steam combined cycle unit to improve the steam parameters of a reheating system under different operating conditions.
Preferably, the method further comprises: and controlling the output temperature of the final-stage reheater of the waste heat boiler to be matched with the load capacity value of the gas-steam combined cycle unit.
Preferably, the system comprises:
the load value acquisition unit is used for acquiring an actual power value and a target power value of the gas-steam combined cycle unit;
a load control unit for controlling the load of the gas turbine according to the deviation between the actual power value and the target load value so that the actual power value is consistent with the target load value;
preferably, the system further comprises:
the load distribution unit is used for correcting the load proportion of the gas turbine, the waste heat boiler and the steam turbine according to the actual operation condition of the gas-steam combined cycle unit;
a load change rate calculation unit for automatically calculating the load change rate of the gas-steam combined cycle unit according to the upper limit and the lower limit of the load change rate of the gas turbine, the exhaust temperature and the change rate of the steam turbine cylinder temperature,
wherein the load control unit controls the synchronous load-up of the gas turbine and the steam turbine according to the load change rate.
Preferably, the system further comprises: the high-pressure reheating system and the reheating system are respectively divided into an inter-stage temperature reduction system and a final-stage temperature reduction system, the inter-stage temperature reduction system is used for controlling the temperature of steam entering an inlet of a final superheater and an inlet of a reheater, but the difference between the exhaust temperature of a combustion engine and the temperature of high-pressure main steam and the temperature of heat re-heating is too large, and the inter-stage temperature reduction system and the final-stage temperature reduction system of the reheater are arranged for ensuring the superheat degree of the steam entering the final-stage high-pressure superheater and the reheater, and the inter-stage temperature reduction system cannot reach the steam inlet temperature required by a steam turbine during starting.
Preferably, the system further comprises: the desuperheating water of the reheater interstage and final stage desuperheating system is extracted by a medium pressure water supply pump outlet pipeline, the desuperheating water regulating valve and the desuperheating device spray head enter the desuperheating device pipeline, and the desuperheating water of the high pressure interstage and final stage desuperheating system is extracted by a traditional high pressure water supply pump outlet pipeline, is controlled to be extracted from an outlet of the high pressure coal economizer 2, and enters the desuperheating device pipeline through the desuperheating water regulating valve and the desuperheating device spray head.
And the final-stage control unit of the waste heat boiler is used for controlling the output temperature of a final-stage reheater of the waste heat boiler, and is matched with the load capacity value of the gas-steam combined cycle unit.
Preferably, the system further comprises: and the sequential control start-stop unit is used for controlling sequential control start-stop with breakpoint confirmation under the working conditions of cold start, warm start, hot start and normal stop of the steam turbine and controlling the load-lifting rate of the gas turbine under the working conditions of diffusion combustion, mixed combustion and premixed combustion.
Preferably, the system further comprises: and the unit load capacity calculation unit is used for calculating each maximum load capacity value which can be borne by the gas-steam combined cycle unit under different operation conditions, and limiting the load of the gas-steam combined cycle unit under different operation conditions to the corresponding maximum load capacity value.
Preferably, the system further comprises: the reheating steam temperature is improved through combustion adjustment of the gas turbine, optimization of an arrangement mode and a temperature reduction mode of a heating surface of the waste heat boiler, upgrading of materials of heat components of the steam turbine, application of new materials of related thermodynamic systems and optimization of an intelligent control system, so that the power generation efficiency of the unit is improved.
Compared with the prior art, the method has the advantages that by adopting the scheme, the characteristic that the exhaust gas temperature of the gas turbine is higher at partial load is utilized, and the final-stage reheater can be arranged on the first-stage heating surface by adjusting the arrangement of the heating surface of the waste heat boiler; improving the steam parameters of a reheating system under the working condition of partial load so as to improve the efficiency of the combined cycle unit; the material is upgraded to adapt to the steam parameters of the reheating system with higher parameters; the design improvement of the temperature-reducing water system is adopted to adapt to a high-parameter thermodynamic system.
Drawings
FIG. 1 is a flow chart of a control method of one embodiment of the present invention;
FIG. 2 is a schematic flow chart illustrating a method for controlling the load of the gas turbine according to the deviation between the actual power value and the target load value in the control method of the embodiment of FIG. 1 of the present invention, so that the actual power value is consistent with the target load value;
FIG. 3 is a schematic flow diagram of a method for upgrading waste heat boiler final stage reheater material to accommodate higher waste heat boiler outlet steam temperature steps in accordance with the embodiment of FIG. 1;
fig. 4 is a block diagram illustrating a control system according to the embodiment of fig. 1.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
In the description herein, references to the terms "an embodiment," "one embodiment," and "one implementation," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or implementation is included in at least one embodiment or example implementation of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or implementation. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or implementations.
As shown in fig. 1-3, one embodiment of the present invention is,
1. the method and the system for controlling and improving the effect of the wide-load operation of the fuel gas and steam combined cycle peak shaving unit are characterized by comprising the following steps of:
s1, acquiring an actual power value and a target power value of the gas-steam combined cycle unit;
s2, raising the temperature of air entering an air inlet of an air inlet module of the gas-steam combined cycle unit;
s3, controlling the load of the gas turbine according to the deviation between the actual power value and the target load value, so that the actual power value is consistent with the target load value;
s4, upgrading the reheater material at the final stage of the waste heat boiler to adapt to higher outlet steam temperature of the waste heat boiler;
and S5, operating the gas-steam combined cycle unit by utilizing the air with the raised temperature.
The step S3 further includes:
s31, correcting the load proportion of the gas turbine and the exhaust-heat boiler-steam turbine according to the actual operation condition of the gas-steam combined cycle unit;
and S32, automatically calculating the load change rate of the gas-steam combined cycle unit according to the upper limit and the lower limit of the load change rate of the gas turbine, the exhaust temperature and the change rate of the steam turbine cylinder temperature, and controlling the synchronous load increase of the gas turbine and the steam turbine according to the load change rate.
And S33, controlling the sequential start and stop with breakpoint confirmation of the steam turbine under the working conditions of cold start, warm start, hot start and normal stop, and controlling the load-lifting rate of the gas turbine under the working conditions of diffusion combustion, mixed combustion and premixed combustion.
The step S32 further includes:
s321, calculating the maximum load capacity values which can be borne by the gas-steam combined cycle unit under different operation conditions, and enabling the gas-steam combined cycle unit to improve the steam parameters of a reheating system under different operation conditions.
The step S4 further includes:
and S41, controlling the output temperature of the final reheater of the waste heat boiler to be matched with the load capacity value of the gas-steam combined cycle unit.
As shown in fig. 4, the gas-steam combined cycle plant control system includes:
the load value acquisition unit is used for acquiring an actual power value and a target power value of the gas-steam combined cycle unit;
a load control unit for controlling the load of the gas turbine according to the deviation between the actual power value and the target load value, so that the actual power value is consistent with the target load value;
the system further comprises:
the load distribution unit is used for correcting the load proportion of the gas turbine, the waste heat boiler and the steam turbine according to the actual operation condition of the gas-steam combined cycle unit;
a load change rate calculation unit for automatically calculating the load change rate of the gas-steam combined cycle unit according to the upper limit and the lower limit of the load change rate of the gas turbine, the exhaust temperature and the change rate of the steam turbine cylinder temperature,
wherein the load control unit controls the synchronous load-up of the gas turbine and the steam turbine according to the load change rate.
The system further comprises:
and the final-stage control unit of the waste heat boiler is used for controlling the output temperature of a final-stage reheater of the waste heat boiler, and is matched with the load capacity value of the gas-steam combined cycle unit.
The system further comprises: and the sequential control start-stop unit is used for controlling sequential control start-stop with breakpoint confirmation under the working conditions of cold start, warm start, hot start and normal stop of the steam turbine and controlling the load-lifting rate of the gas turbine under the working conditions of diffusion combustion, mixed combustion and premixed combustion.
The system further comprises: and the unit load capacity calculation unit is used for calculating each maximum load capacity value which can be borne by the gas-steam combined cycle unit under different operation conditions, and limiting the load of the gas-steam combined cycle unit under different operation conditions to the corresponding maximum load capacity value.
Furthermore, because the parameters of the high-temperature reheat steam are improved, the selection of system materials such as the reheat steam, bypass steam, drainage and the like is influenced, and the design of a reheater temperature reduction water system in a water supply system is also influenced.
The choice of pipe material depends mainly on the media parameters. In the conventional scheme, the design temperature of high-temperature reheat steam, steam before an intermediate-pressure bypass valve and related drain pipelines of the F-grade gas-steam combined cycle unit is generally 572 ℃, so that pipelines made of P91 (the recommended use limit temperature is 593 ℃) can be adopted. In the high-performance scheme, the temperature of the high-temperature reheat steam pipeline is raised to 605 ℃ under the partial load working condition, the design temperature reaches 610 ℃, although the pipeline made of the P91 material can still be used, the allowable stress of the material is reduced due to the temperature rise, and the wall thickness of the pipeline is greatly increased. For a unit with a heavy peak regulation task, the unit is changed into a load rate due to the influence of excessive wall thickness of a steam-water pipeline, and the fatigue failure of a pipe is a big problem. Meanwhile, in japan in the early 1990 s, it was found that P91 steel could not satisfy the requirement of long-term safe operation when the service temperature exceeded 600 ℃. Therefore, the pipeline material needs to be reselected so as to adapt to the frequent start-stop working condition of the peak shaving unit and ensure the safety of the long-term operation of the unit;
in order to control the outlet temperature of the high-pressure main steam and the hot main steam to match the starting parameters of the steam turbine, the project is provided with two stages of high-pressure and reheating temperature reduction systems. The high-pressure reheating two-stage temperature reduction system is divided into an inter-stage temperature reduction system and a final-stage temperature reduction system. The purpose of the inter-stage attemperation system is to control the temperature of the steam entering the finishing superheater, reheater inlet. However, because the difference between the exhaust temperature of the combustion engine and the temperature of the high-pressure main steam and the heat reheater is too large, and meanwhile, in order to ensure the superheat degree of steam entering a final-stage high-pressure superheater and a reheater, the interstage attemperation cannot reach the steam inlet temperature required by a steam turbine during starting, a final-stage attemperation system of the high-pressure superheater and the reheater is arranged;
in the project, desuperheating water of the reheater interstage and final stage desuperheating systems is extracted from an outlet pipeline of a medium-pressure water supply pump, passes through a desuperheating water regulating valve and a desuperheater spray head and then enters a desuperheater pipeline. The desuperheating water of the high-pressure interstage and final stage desuperheating systems is extracted from an outlet pipeline of a high-pressure water supply pump in the prior art, is adjusted to be extracted from an outlet of the high-pressure economizer 2, and enters a pipeline of the desuperheater through a desuperheating water adjusting valve and a desuperheater spray head. Thus, the temperature reduction requirement is met, and the high-pressure main steam flow is increased, so that the boiler is matched with the thermal equilibrium diagram under the working conditions that the performance of the boiler is guaranteed to be 100% and 75% pure condensation is carried out;
the reheating steam temperature is improved by comprehensive measures such as combustion adjustment of a gas turbine, arrangement mode and temperature reduction mode optimization of a heating surface of a waste heat boiler, material upgrading of a heat component of the steam turbine, application of a new material of a related thermodynamic system, optimization of an intelligent control system and the like, so that the power generation efficiency of a unit is improved
The invention is applied to a gas-steam combined cycle unit, and reasonably compensates the difference between the load change speed of the gas turbine and the load change speed of the steam turbine by automatically adjusting the load distribution of the gas turbine and the steam turbine, thereby not only optimizing the unit operation mode and ensuring the safe operation of the unit, but also reducing the operation amount of operators, effectively reducing the unplanned shutdown times caused by the misoperation of the operators, and indirectly creating certain economic benefit.
Preferably, according to a large number of combined cycle power plant design experiences, the end difference of 20-35 ℃ between the exhaust gas temperature of a common gas turbine and the main steam temperature of a steam turbine needs to be ensured, and the thermodynamic conditions of boiler design and operation are met. When the exhaust gas temperature of the gas turbine is raised to 630 ℃, the exhaust gas temperature is optimized and raised simultaneously by matching with the parameters of the waste heat boiler, and the reheating steam temperature of the steam turbine can be raised to more than 600 ℃. Therefore, the steam turbine reheat steam parameter raising scheme has thermodynamic feasibility, and proper part materials are usually selected to ensure the performance of the steam turbine in long-term reliable operation. The lower graph illustrates the 100,000h creep strength change difference for the selected material class.
The optimization of the running mode of the unit greatly improves the automation level of the unit, the whole starting process needs few manual operations, once the unit is started by receiving the order, the unit can be fully loaded in a short time, and the stability of the unit is enhanced.
The load control of the whole set of unit is designed and put into operation, the reasonable distribution of the load born by the gas turbine and the steam turbine is completed, the monitoring and the control of the main steam pressure of the waste heat boiler are completed, the primary frequency modulation function of the set is realized, and the practical value is realized for realizing the safe and stable operation of the gas turbine and the steam turbine and optimizing the peak regulation capability of the gas turbine and the steam turbine.
The control strategy of the gas-steam combined cycle unit provided by the invention aims at the control characteristics of a gas turbine, a waste heat boiler, a steam turbine and the like, realizes the integral control function requirement of the combined cycle unit, ensures the requirement of the rapid load lifting of the whole combined cycle unit, and meets the requirement of a power grid dispatching department. The control strategy has clear logic, strong controllability and strong universality and practicability.
Preferably, alloy steels with lower creep resistance requirements (e.g., 1% CrMoV, including G17CrMoV5-10) can only be used at temperatures below 565 ℃ and cannot meet the requirements for higher steam temperatures. Thus, material development and qualification development projects over the past two decades have focused on 9-11% Cr steels, also known as creep strength enhanced ferritic steels (CSEF) (e.g., ASTM pipe, grades P91, P92). The method aims to further improve the high-temperature performance of the series of alloy steels by optimizing the components of alloy elements and adding new alloy elements such as niobium (Nb) and nitrogen (N) on the basis of 12 percent CrMoV. The casting material GX12CrMoVNbN9-1 has good creep resistance performance when the application temperature is raised to 620 ℃ by virtue of quenching and tempering and refining and 9-11% of Cr alloy components, and is already applied to important parts such as valves, cylinders and the like for many years.
The closed-loop control of the total power of the combined cycle unit is realized, the uniform dispatching of the power generation power of the whole plant is facilitated, and a realization platform is provided for primary frequency modulation.
Furthermore, the exhaust-heat boiler is matched with a gas turbine, the exhaust gas temperature of the gas turbine is up to 630 ℃, and compared with a conventional F-level unit, the exhaust gas temperature of the gas turbine is greatly improved. The exhaust temperature of the gas turbine is higher mainly through the following two designs in the development process of the waste heat boiler:
the final-stage reheater is arranged on the first-stage heating surface and is closest to the outlet of the gas turbine, and the final-stage reheater directly bears the scouring of high-temperature flue gas at 630 ℃, so that the temperature of the outlet of the hot reheating main steam is up to 605 ℃, which is nearly 40 ℃ higher than that of the conventional reheater.
The high-pressure superheater desuperheating water is extracted from the outlet of a high-pressure feed water pump in the prior art and is designed to be extracted from the interstage of a high-pressure economizer, so that the parameters of a high-pressure main steam outlet are improved.
The reasonable distribution of the load requirements is realized, and the combined cycle is utilized to work to the maximum extent. The requirement of rapidity of lifting load is met, and the economic design of the combined cycle unit is matched. Upgrading the material of a final-stage reheater of the waste heat boiler to adapt to higher outlet steam temperature of the waste heat boiler; the gas-steam combined cycle unit is operated by utilizing the air with the temperature raised, so that the energy reuse rate is improved.
In the embodiment, the final reheater of the waste heat boiler is arranged on the first-stage heating surface, namely the side closest to the combustion engine, and the direct combustion engine discharges smoke. Under the partial load working condition, because the exhaust gas temperature of the combustion engine is higher than the rated load working condition, the high-temperature reheat steam can be increased to 605 ℃ (reaching the ultra-supercritical unit level). On the side of the steam turbine, the combined cycle efficiency is improved finally by upgrading the materials such as the inner cylinder and the rotor of the medium-pressure steam turbine, the medium-pressure main steam valve, the high-temperature reheating steam pipeline, the valves and the like.
In the system design, a high-temperature reheat steam system (comprising a steam turbine bypass system and a corresponding drainage system) and a temperature-reducing water system are also improved. The high-temperature reheat steam, the steam before the medium-pressure bypass valve and the drain pipeline thereof are made of P92 materials, and the inlet section of the medium-pressure bypass valve, the drain system valve of the high-temperature reheat steam pipeline and the like are made of F92 materials; the desuperheating water of the high-pressure interstage and final stage desuperheating systems is extracted from an outlet pipeline of a high-pressure water supply pump in the prior art, is adjusted to be extracted from an outlet of a high-pressure coal economizer, and enters a pipeline of the desuperheater through a desuperheating water adjusting valve and a desuperheater spray head.
The technical scheme of the invention also has the following beneficial effects:
1. revolutionary innovation is carried out on the basis of the principle and the characteristics of the combined cycle, and the wide load efficiency improvement of the combined cycle unit is realized;
2. through estimation, the initial investment is only increased by 250 ten thousand yuan (including the cost of upgrading materials such as an inner cylinder and a rotor of a medium-pressure steam turbine, a medium-pressure main steam valve, a high-temperature reheating steam pipeline, a valve and the like), but the total output of the combined cycle is slightly increased, the heat efficiency is improved by 0.16%, the generating benefit of a unit can be increased, and the fuel cost is reduced. The final annual income can be as high as 150 ten thousand yuan. The static recovery period is less than 2 years.
3. The system is simple and reliable from the control point of view without adding extra systems.
4. The application range is wide, the efficiency is improved from 50% to 100% under the working condition, and the benefit is optimal when the working condition is 75%. According to research, the annual average load rate of the combined cycle unit serving as a peak regulation function is about 75%. The scheme of the invention is fit with the actual operation of the existing peak shaving power plant.
Although the present disclosure has been described above, the scope of the present disclosure is not limited thereto, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and such changes and modifications will fall within the scope of the present disclosure.
Claims (10)
1. The method and the system for controlling and improving the effect of the wide-load operation of the fuel gas and steam combined cycle peak shaving unit are characterized by comprising the following steps of:
acquiring an actual power value and a target power value of the gas-steam combined cycle unit;
raising the temperature of air entering an air inlet of an air inlet module of the gas-steam combined cycle unit;
controlling the load of the gas turbine according to the deviation of the actual power value and the target load value, so that the actual power value is consistent with the target load value;
arranging a final-stage reheater on the first-stage heating surface, wherein the final-stage reheater is closest to the outlet of the gas turbine and directly bears the scouring of high-temperature flue gas;
upgrading the material of a final-stage reheater of the waste heat boiler to adapt to higher outlet steam temperature of the waste heat boiler;
the desuperheating water of the high-pressure superheater is extracted from the outlet of the high-pressure feed water pump and is extracted from the interstage of the high-pressure economizer, so that the outlet parameters of high-pressure main steam are improved;
and operating the gas-steam combined cycle unit by utilizing the air with the temperature raised.
2. The method and system for controlling and increasing the efficiency of the wide-load operation of the gas-steam combined cycle peak shaving unit according to claim 1, characterized in that the method further comprises the following steps:
controlling the load proportion of a gas turbine and a waste heat boiler-steam turbine according to the actual operation condition of the gas-steam combined cycle unit;
and automatically calculating the load change rate of the gas-steam combined cycle unit according to the load change rate of the gas turbine, the upper limit and the lower limit of the load change rate of the gas turbine, the exhaust temperature and the steam turbine cylinder temperature change rate, and controlling the synchronous load rise of the gas turbine and the steam turbine according to the load change rate.
3. The method and system for controlling and increasing the efficiency of the wide-load operation of the gas-steam combined cycle peak shaving unit according to claim 1, characterized in that the method further comprises the following steps:
the method comprises the steps of controlling the sequential control start and stop with breakpoint confirmation under the working conditions of cold start, warm start, hot start and normal stop of the steam turbine, and controlling the load-lifting rate of the gas turbine under the working conditions of diffusion combustion, mixed combustion and premixed combustion.
4. The method and system for controlling and increasing the efficiency of the wide-load operation of the gas-steam combined cycle peak shaving unit according to claim 1, characterized in that the method further comprises the following steps: and calculating the maximum load capacity values which can be borne by the gas-steam combined cycle unit under different operating conditions, and enabling the gas-steam combined cycle unit to improve the steam parameters of a reheating system under different operating conditions.
5. The method and system for controlling and increasing the efficiency of the wide-load operation of the gas-steam combined cycle peak shaving unit according to claim 1, characterized in that the method further comprises the following steps: and controlling the output temperature of the final-stage reheater of the waste heat boiler to be matched with the load capacity value of the gas-steam combined cycle unit.
6. The method and system for controlling and improving the effect of the wide load operation of the fuel gas and steam combined cycle peak shaving unit are characterized in that the system comprises:
the load value acquisition unit is used for acquiring an actual power value and a target power value of the gas-steam combined cycle unit;
a load control unit for controlling the load of the gas turbine according to the deviation between the actual power value and the target load value so that the actual power value is consistent with the target load value;
the load distribution unit is used for correcting the load proportion of the gas turbine, the waste heat boiler and the steam turbine according to the actual operation condition of the gas-steam combined cycle unit;
a load change rate calculation unit for automatically calculating the load change rate of the gas-steam combined cycle unit according to the upper limit and the lower limit of the load change rate of the gas turbine, the exhaust temperature and the change rate of the steam turbine cylinder temperature,
the waste heat boiler final-stage control unit is used for controlling the output temperature of a waste heat boiler final-stage reheater and is matched with the load capacity value of the gas-steam combined cycle unit;
wherein the load control unit controls the synchronous load-up of the gas turbine and the steam turbine according to the load change rate.
7. The method and system for controlling and increasing the efficiency of the wide-load operation of the gas-steam combined cycle peak shaving unit according to claim 1, wherein the system further comprises: the high-pressure reheating system and the reheating system are respectively divided into an inter-stage temperature reduction system and a final-stage temperature reduction system, the inter-stage temperature reduction system is used for controlling the temperature of steam entering an inlet of a final superheater and an inlet of a reheater, but the difference between the exhaust temperature of a combustion engine and the temperature of high-pressure main steam and the temperature of heat re-heating is too large, and the inter-stage temperature reduction system and the final-stage temperature reduction system of the reheater are arranged for ensuring the superheat degree of the steam entering the final-stage high-pressure superheater and the reheater, and the inter-stage temperature reduction system cannot reach the steam inlet temperature required by a steam turbine during starting.
8. The method and system for controlling and increasing the efficiency of the wide-load operation of the gas-steam combined cycle peak shaving unit according to claim 1, wherein the system further comprises: the desuperheating water of the reheater interstage and final stage desuperheating system is extracted by a medium pressure water supply pump outlet pipeline, the desuperheating water regulating valve and the desuperheating device spray head enter the desuperheating device pipeline, and the desuperheating water of the high pressure interstage and final stage desuperheating system is extracted by a traditional high pressure water supply pump outlet pipeline, is controlled to be extracted from an outlet of the high pressure coal economizer 2, and enters the desuperheating device pipeline through the desuperheating water regulating valve and the desuperheating device spray head.
9. The method and system for controlling and increasing the efficiency of the wide-load operation of the gas-steam combined cycle peak shaving unit according to claim 6, wherein the system further comprises: the sequential control start-stop unit is used for controlling sequential control start-stop with breakpoint confirmation under the working conditions of cold start, warm start, hot start and normal stop of the steam turbine and controlling the load-lifting rate of the gas turbine under the working conditions of diffusion combustion, mixed combustion and premixed combustion;
and the unit load capacity calculation unit is used for calculating each maximum load capacity value which can be borne by the gas-steam combined cycle unit under different operation conditions, and limiting the load of the gas-steam combined cycle unit under different operation conditions to the corresponding maximum load capacity value.
10. The method and system for controlling and increasing the efficiency of the wide-load operation of the gas-steam combined cycle peak shaving unit according to claim 6, wherein the system further comprises: the reheating steam temperature is improved through combustion adjustment of the gas turbine, optimization of an arrangement mode and a temperature reduction mode of a heating surface of the waste heat boiler, upgrading of materials of heat components of the steam turbine, application of new materials of related thermodynamic systems and optimization of an intelligent control system, so that the power generation efficiency of the unit is improved.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101769180A (en) * | 2009-01-05 | 2010-07-07 | 华北电力科学研究院有限责任公司 | Control method and system thereof for biaxial gas-steam combined cycle unit |
| CN106439770A (en) * | 2016-09-20 | 2017-02-22 | 广东电网有限责任公司电力科学研究院 | Control method for steam temperature of meager coal boiler of 1045MW ultra supercritical unit |
| CN206001429U (en) * | 2016-08-29 | 2017-03-08 | 哈尔滨锅炉厂有限责任公司 | A kind of double reheat π type boiler |
| CN106989611A (en) * | 2017-05-18 | 2017-07-28 | 中冶华天南京工程技术有限公司 | A kind of coke-stove gas and dry coke quenching residual heat integrative electricity generation system |
| CN111256106A (en) * | 2020-03-30 | 2020-06-09 | 西安热工研究院有限公司 | Metal wall temperature adjusting system for high-temperature heating surface |
| CN113958413A (en) * | 2021-11-15 | 2022-01-21 | 西安热工研究院有限公司 | Gas-steam combined cycle intake fuel coupling heating system and method |
-
2022
- 2022-05-25 CN CN202210578513.5A patent/CN114837810B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101769180A (en) * | 2009-01-05 | 2010-07-07 | 华北电力科学研究院有限责任公司 | Control method and system thereof for biaxial gas-steam combined cycle unit |
| CN206001429U (en) * | 2016-08-29 | 2017-03-08 | 哈尔滨锅炉厂有限责任公司 | A kind of double reheat π type boiler |
| CN106439770A (en) * | 2016-09-20 | 2017-02-22 | 广东电网有限责任公司电力科学研究院 | Control method for steam temperature of meager coal boiler of 1045MW ultra supercritical unit |
| CN106989611A (en) * | 2017-05-18 | 2017-07-28 | 中冶华天南京工程技术有限公司 | A kind of coke-stove gas and dry coke quenching residual heat integrative electricity generation system |
| CN111256106A (en) * | 2020-03-30 | 2020-06-09 | 西安热工研究院有限公司 | Metal wall temperature adjusting system for high-temperature heating surface |
| CN113958413A (en) * | 2021-11-15 | 2022-01-21 | 西安热工研究院有限公司 | Gas-steam combined cycle intake fuel coupling heating system and method |
Non-Patent Citations (2)
| Title |
|---|
| 薛丽华等: "F级余热锅炉蒸汽温度控制策略", 燃气轮机技术, vol. 26, no. 04, 16 December 2013 (2013-12-16), pages 14 - 16 * |
| 贾斌等: "150MW级燃气―蒸汽联合循环机组调峰方式探讨", 内蒙古电力技术, vol. 28, no. 2, 28 November 2010 (2010-11-28), pages 59 - 61 * |
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