A peak-shaving system and peak-shaving method for air separation device in thermal power plant

Abstract

The invention discloses a peak-shaving system for an air separation device in a thermal power plant. The peak-shaving system comprises a thermal power plant generator set, the thermal power plant generator set comprises a large steam turbine (2), a generator (3) and a peak-shaving control module, the peak-shaving control module receives a peak-shaving instruction from a power grid dispatching center; the air separation device is connected to a steam pipeline of the generator (3) and / or the thermal power plant generator set, the peak-shaving control module can transfer the power of the generator (3) and / or the steam of the thermal power plant group to the air separation device to drive the air separation device; the invention effectively utilizes the peak-shaving surplus electricity and heat energy of the thermal power generator set to meet the equipment energy supply of the air separation device, reduces the energy consumption of the external supplementary driving of the air separation device, avoids resource waste, improves energy utilization, and transforms a modern thermal power plant into a comprehensive factory for electric energy, heat energy, compressed air energy and various air separation gas products.

Description

Technical Field

[0001] The present invention relates to the technical field of air separation and thermal power peak regulation, and more specifically, to a system and a peak regulation method for supplying energy to an air separation device by using peak regulation electricity or peak regulation steam of a thermal power plant. Background Art

[0002] At present, my country's power system has abundant electricity production and capacity, and gas turbines, pumped storage, etc. can be used for peak regulation to solve the problem of power shortage. At present, there is a prominent contradiction between the peak regulation of the power grid and the flexibility of thermal power units, and the power grid's ability to absorb new energy such as wind power, photovoltaic power, hydropower and nuclear power is insufficient.

[0003] In the existing technology, the peak load regulation of thermal power plants has become a prominent contradiction in the operation of power grids. At present, the flexible peak load regulation transformation of domestic thermal power plants is aimed at winter heating units, while how to carry out summer peak load regulation is a difficult problem facing many thermal power plants. In order to meet the peak load regulation needs of the power grid, minimize the waste of energy during the peak load regulation process, and survive the fierce competition of power plants, it is imperative to carry out in-depth peak load regulation reforms.

[0004] On the other hand, large-scale air separation units are increasingly used in the steel, chemical and synthetic ammonia industries, and more and more new large-scale air separation unit projects are being implemented, and their energy consumption accounts for an increasing proportion of the total social energy consumption year by year.

[0005] Air separation equipment uses air as raw material and separates air through any of the three methods: cryogenic air separation, pressure swing adsorption or membrane separation. The most mature application is the cryogenic air separation method, which converts air into liquid through compression cycle deep freezing, and then gradually separates inert gases such as oxygen, nitrogen and argon from the liquid air through distillation.

[0006] At present, there are many types of air separation equipment produced in my country. There are devices for producing gaseous oxygen and gaseous nitrogen, such as oxygen generators; there are also devices for producing liquid oxygen and liquid nitrogen. But in terms of its basic process, there are four main types, namely high pressure, medium pressure, high and low pressure and full low pressure process. In the early days, the production scale of air separation equipment in my country could only produce 20m 3 / h (oxygen) oxygen generator, the current large-scale air separation equipment has the ability to produce 20,000m 3 / h、30000m 3 / h and 50000m 3 / h (oxygen) capacity.

[0007] From the process flow, air separation equipment can be divided into 5 basic systems: Impurity purification system: mainly through air filters and molecular sieve absorbers and other devices to purify mechanical impurities, moisture, carbon dioxide, acetylene, etc. mixed in the air. Air cooling and liquefaction system: mainly composed of air compressors, heat exchangers, expanders and air throttle valves, etc., which play the role of deep freezing the air. Air distillation system: The main components are distillation towers (upper tower, lower tower), condenser evaporator, subcooler, liquid air and liquid nitrogen throttle valves; they play the role of separating various components in the air. Heating and blowing system: The purification system is regenerated by heating and blowing. Instrument control system: The entire process is controlled by various instruments. In summary, the high energy consumption of large-scale air separation units has become an important bottleneck hindering the development of the air separation industry.

[0008] In view of this, the present invention is proposed. Summary of the invention

[0009] In view of the deficiencies in the prior art, the present invention aims to provide a peak-shaving system for an air separation unit in a thermal power plant with high energy utilization rate, which utilizes peak-shaving electricity or peak-shaving steam to power an air separation unit, and utilizes the gas products of the air separation unit to provide cooling, heat, compressed air and air separation terminal gas products to the outside.

[0010] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical scheme:

[0011] A peak-shaving system for an air separation device in a thermal power plant, the peak-shaving system comprising a thermal power plant generator set, the thermal power plant generator set comprising a large steam turbine, a generator and a peak-shaving control module, the peak-shaving control module receiving peak-shaving instructions from a power grid dispatching center; the air separation device is connected to the steam pipeline of the generator and / or the thermal power plant generator set, the peak-shaving control module can transfer the electricity of the generator and / or the steam of the thermal power plant group to the air separation device to drive the air separation device.

[0012] Preferably, the driving steam for the air separation device comes from the steam extraction pipeline of the large steam turbine of the power plant generator set or the main steam pipeline of the power plant.

[0013] Preferably, the peak-shaving system includes a small steam turbine of a steam-driven air separation device, and the small steam turbine is connected to the steam extraction pipeline of a large steam turbine of a thermal power generator set or the main steam pipeline of a power plant; the peak-shaving control module can control the amount of steam supplied to the small steam turbine by the peak-shaving steam to drive the small steam turbine, and the small steam turbine performs work to drive the air separation device under the drive of the peak-shaving steam.

[0014] Preferably, the air separation device includes a compressor; the small steam turbine is connected to the compressor via a coupling to drive the compressor.

[0015] Preferably, the compressor is an air compressor and / or a supercharger.

[0016] Preferably, the air separation device comprises a compressor; the generator is connected to the compressor to drive the compressor with electricity.

[0017] Preferably, the compressor is at least one of an air compressor, a supercharger, and a product supercharger.

[0018] Preferably, the compressed air generated by the air compression process of the air separation device is used as an industrial driving compressed air source for a thermal power plant or a nearby industrial park.

[0019] Preferably, the product booster includes an oxygen compressor and / or a nitrogen compressor; the air separation device includes a precooling system and a cold box, the precooling system is connected to the air compressor, and the cold box is connected to the oxygen compressor and / or the nitrogen compressor; the precooling system and / or the cold box are connected to the refrigeration circulating water pipeline of the external refrigeration equipment of the thermal power plant, and can transfer the surplus cooling capacity to the refrigeration circulating water pipeline of the external refrigeration equipment. The air separation device includes a low-temperature liquid phase storage tank or storage tank for storing the final air separation product.

[0020] A peak-shaving method for an air separation device in a thermal power plant, the peak-shaving method uses the peak-shaving system described above, and the specific steps of the peak-shaving method are as follows:

[0021] S1: The thermal power plant receives a deep peak load reduction or load increase instruction from the power grid dispatching center. The power it increases or decreases for online power is the peak load P. 调峰 ;

[0022] S2: Select the peak-shaving driving mode of the air separation device. If it is the electric driving mode, execute step S3; if it is the peak-shaving steam driving mode, execute step S4;

[0023] S3: The peak load control module adjusts the power consumption of the air separation device so that it can respond to the peak load instruction of the power grid in time. The specific formula is:

[0024] P 调峰 =P 空耗’ -P 空耗0 , where: P 空耗0 is the power consumption of the air separation unit before peak load regulation, P 空耗’ is the power consumption of the air separation unit after peak load regulation;

[0025] S4: The peak-shaving system includes a steam supply regulating valve, which regulates the peak-shaving steam source flow rate F supplied to the air separation device. 调峰 ;

[0026] According to the situation of the peak-shaving system, select the optimal peak-shaving steam source. The flow rate F of this peak-shaving steam source is调峰 and peak load P 调峰 The relationship formula is:

[0027] F 调峰 =0.278*P 调峰 / (△H 剩余 *η 大汽机 *η e )

[0028] Where: P 调峰 is the peak load, in kW;

[0029] △H 剩余 It is the residual enthalpy difference between the steam extracted from the large steam turbine and the exhaust enthalpy value, in kJ / kg. When the steam is extracted before reheating, the residual enthalpy difference includes the enthalpy rise caused by the reheater.

[0030] η 大汽机 is the relative internal efficiency of the large steam turbine;

[0031] η e is the generator efficiency;

[0032] S5: According to the calculation result of S4, F 调峰 , adjust the opening of the steam supply regulating valve to provide peak steam source flow F 调峰 , so that thermal power units can respond to grid peak load regulation instructions.

[0033] Beneficial Effects

[0034] 1. Effectively utilize the peak-load surplus electricity and heat energy of thermal power generating units to meet the energy supply of air separation equipment, reduce the energy consumption of external supplementary driving air separation equipment, avoid energy waste, improve energy utilization, and transform modern thermal power plants into comprehensive plants for electricity, heat, compressed air and various air separation gas products;

[0035] 2. The surplus cold capacity of the cold box in the air separation unit is used to cool the air conditioning circulating water, which is used for air conditioning and refrigeration in the thermal power plant area or nearby buildings;

[0036] 3. The compressed air generated by the air compression process in the air separation device can be used as a source of industrial driving compressed air for thermal power generating units or nearby industrial parks; this method also realizes the storage of electric energy in disguise, which can supplement the online power of thermal power plants and alleviate the problems of grid balance and peak-valley difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the first embodiment of the peak load regulation system of the air separation device of the thermal power plant of the present invention;

[0038] Figure 2This is another structural schematic diagram of the first embodiment of the peak load regulation system of the air separation device of a thermal power plant according to the present invention;

[0039] Figure 3 It is a schematic diagram of the second embodiment of the peak load regulation system of the air separation device of the thermal power plant of the present invention;

[0040] Figure 4 It is a schematic diagram of the third embodiment of the peak load regulation system of the air separation device of the thermal power plant of the present invention;

[0041] Figure 5 It is a schematic diagram of a fourth embodiment of a peak load regulation system for an air separation device in a thermal power plant according to the present invention;

[0042] Figure 6 The figure is a schematic diagram of a specific process of the peak load regulation method of the air separation device in a thermal power plant according to the present invention.

[0043] Description of Reference Numerals

[0044] In order to further clearly illustrate the structure of the present invention and the connection relationship between the various components, the following figure numbers are given and explained.

[0045] Coal-fired boiler 1, large steam turbine 2, generator 3, power grid 4, air compressor 5, small steam turbine 6, precooling system 7, booster 8, molecular sieve 9, expander 10, plate heat exchanger 11, cold box 12, oxygen compressor 13, nitrogen compressor 14, storage tank 15.

[0046] Through the above-mentioned description of the accompanying drawings, combined with the embodiments of the present invention, the technical solution of the present invention can be more clearly understood and explained. DETAILED DESCRIPTION

[0047] The present invention is further described below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the scope of protection claimed in the present invention is not limited to the scope described in the specific embodiments. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other arbitrarily without conflict.

[0048] Embodiment 1

[0049] A peak load regulation system for air separation unit in thermal power plant, such as Figure 1As shown, the peak-shaving system includes a thermal power plant generator set, which includes a coal-fired boiler 1, a large steam turbine 2, a generator 3 and its ancillary equipment, and a power plant centralized control system; the power plant centralized control system includes a peak-shaving control module; the peak-shaving control module is respectively connected to the thermal power generator set, the power grid 4 and the air separation device to receive the peak-shaving instructions from the power grid dispatching center, control the operation and stop of the air separation device, and meet the peak-shaving demand of the power grid 4 for the thermal power plant. When the thermal power plant generator set is in operation, the coal-fired boiler 1 operates and transmits steam to the large steam turbine 2, which is driven by the high-temperature steam to do work and drives the generator 3 to generate electricity, and the peak-shaving control module controls the generator 3 to supply electricity to the power grid 4 as required.

[0050] The peak-shaving system includes a small steam turbine 6, which is connected to the extraction pipe of the large steam turbine 2 of the thermal power generating unit or the main steam pipe of the power plant (connected to the boiler feed water pipe and condensate pipe of the thermal power generating unit); the air separation device includes an air compressor 5 and a supercharger 8; the small steam turbine 6 is connected to the air compressor 5 and the supercharger 8 respectively; the peak-shaving control module can control the amount of steam supplied to the small steam turbine 6 by the extraction steam or main steam of the large steam turbine 2, so as to drive the small steam turbine 6. The small steam turbine 6 works under the drive of the peak-shaving steam to drive the rotating components of the air compressor 5 and the supercharger 8 to rotate.

[0051] The air separation device adopts any one or a combination of the three methods of cryogenic air separation, pressure swing adsorption or membrane separation to produce air separation related gas products. Preferably, the air separation device adopts a cryogenic process, and the air separation device includes a precooling system 7, a molecular sieve 9, an expander 10, a plate heat exchanger 11 and a cold box 12. The air compressor 5, the precooling system 7, the booster 8, the molecular sieve 9, the expander 10, the plate heat exchanger 11 and the cold box 12 are connected in sequence. The cold box 12 is connected to the product booster and the storage tank 15; the product booster includes an oxygen compressor 13 and a nitrogen compressor 14. The storage tank 15 or the storage tank low-temperature liquid phase storage device can store the final air separation products such as liquid nitrogen, liquid oxygen, liquid argon, etc. obtained by the air separation device. The cold box 12 is provided with a product outlet; the oxygen compressor 13, the nitrogen compressor 14, and the storage tank 15 are connected to the product outlet on the cold box 12, and the gas products obtained are separated by a compressed air separation device to obtain gas products stored in a high-pressure manner (gas products such as oxygen or nitrogen stored in high-pressure cylinders).

[0052] Preferably, the oxygen compressor 13 and the nitrogen compressor 14 are electrically connected to the generator 3 of the thermal power generator set, and the oxygen compressor 13 and the nitrogen compressor 14 can obtain peak-shaving power from the generator 3 through the peak-shaving control module. That is, the power of the generator 3 is supplied to the power grid 4 on the one hand, and on the other hand, the peak-shaving power is supplied to other electrical equipment in the air separation device through the peak-shaving control module, such as the generator 3 supplies power to the oxygen compressor 13 and the nitrogen compressor 14.

[0053] During non-peak hours, the peak-shaving control module obtains peak-shaving steam from the thermal power generator set and transports the peak-shaving steam to the small steam turbine 6 to drive the small steam turbine 6. The small steam turbine 6 drives the air compressor 5 and the supercharger 8 under the drive of the peak-shaving steam to compress and supercharge the air. Figure 1 The small steam turbine 6 used for driving is coaxially connected to the air compressor 5 and the supercharger 8 respectively; the small steam turbine 6 used for driving is connected to the air compressor 5 and the supercharger 8 through a coupling. Figure 2 , or the peak-shaving system is provided with two small steam turbines 6 , one of which is connected to the air compressor 5 , and the other is connected to the supercharger 8 .

[0054] The air compressor 5 extracts air from the atmosphere, and the air enters the precooling system 7 after being compressed; the low-temperature air passing through the precooling system 7 enters the molecular sieve 9, and the cold air filtered from the molecular sieve 9 enters the supercharger 8 for pressurization according to demand; the compressed air passing through the supercharger 8 enters the expander 10, and the cold air passing through the expander 10 reaches the cold box 12 after passing through the plate heat exchanger 11, and the separated gas product is obtained in the cold box 12, and is sent to the user after treatment. The compressed air product can also be stored or transported through a low-temperature liquid phase storage tank, or can be sent to the user through a high-pressure gas cylinder or a high-pressure pipeline pressurized by a supercharger.

[0055] Preferably, the expander 10 in the air separation device is connected to a booster or other device that needs to rotate in the air separation device, and the rotational mechanical energy released by the expansion and refrigeration process of the expander 10 can be used to drive the booster or other rotating device required by the air separation device. The air separation product of the peak-shaving system of the air separation device of the thermal power plant is oxygen, nitrogen, argon or other rare inert gases.

[0056] Preferably, at least one of the cold box 12 and the precooling system 7 is connected to the refrigeration circulating water pipeline of the external air conditioner, and the cold box 12 and the precooling system 7 transfer surplus cooling capacity to the refrigeration circulating water pipeline of the external air conditioner to provide air conditioning refrigeration for the thermal power plant or nearby buildings.

[0057] Preferably, the precooling system 7 is connected to the supercharger 8 to transmit surplus cold air to drive the supercharger 8.

[0058] In this embodiment, all rotating machinery in the air separation device, such as air compressors, boosters, etc., are driven by peak-shaving steam from the power plant, that is, the peak-shaving surplus steam from the power plant during non-peak periods is used to provide power for the air separation device.

[0059] Embodiment 2

[0060] The difference between this embodiment and the first embodiment is that the peak load regulation system does not have a small steam turbine 6, but connects a generator to the air separation device to supply power to the air separation device.

[0061] like Figure 3 As shown, a peak-shaving system for an air separation device in a thermal power plant, the peak-shaving system includes a thermal power plant generator set, the thermal power plant generator set includes a coal-fired boiler 1, a large steam turbine 2, a generator 3 and its ancillary equipment, and a power plant centralized control system; the power plant centralized control system includes a peak-shaving control module; the peak-shaving control module is respectively connected to the thermal power generator set, the power grid 4 and the air separation device to receive the peak-shaving instructions from the power grid dispatching center, control the operation and stop of the air separation device, and meet the peak-shaving demand of the power grid 4 for the thermal power plant. When the thermal power plant generator set is in operation, the coal-fired boiler 1 operates and transmits steam to the large steam turbine 2, the large steam turbine 2 is driven by the high-temperature steam to do work, and drives the generator 3 to generate electricity, and the peak-shaving control module controls the generator 3 to supply electricity to the power grid 4 as required.

[0062] The air separation device includes an air compressor 5 and a supercharger 8; the air compressor 5 and the supercharger 8 are both connected to the generator 3; the peak-shaving control module can transfer the electricity in the generator 3 to the air compressor 5 and the supercharger 8 to drive the rotating components of the air compressor 5 and the supercharger 8 to rotate.

[0063] During non-peak hours, the peak-shaving control module obtains peak-shaving power from the thermal power generator set and delivers the peak-shaving power to the air compressor 5 and the supercharger 8, which serves as the power source for the air compressor 5 and the supercharger 8 to perform air compression and supercharging. That is, the air compressor 5 and the supercharger 8 obtain peak-shaving power from the generator 3 through the peak-shaving control module.

[0064] In this embodiment, all air separation devices are driven by electricity, and all air separation devices fully utilize the peak-shaving surplus electricity of the power plant during the non-peak period of electricity consumption, that is, the peak-shaving surplus electricity of the power plant during the non-peak period of electricity consumption is utilized to provide power for the air separation devices.

[0065] Embodiment 3

[0066] The difference between this embodiment and implementation one is that the air separation device in the peak-shaving system is connected to the steam pipeline of the power plant generator set on the one hand to be driven by the peak-shaving steam of the power plant; and is connected to the generator on the other hand to use the generator to power the air separation device.

[0067] like Figure 4 As shown, in this embodiment, the air separation device of the peak-shaving system is connected to the steam pipeline of the power plant generator set on the one hand, and the peak-shaving control module can pump the peak-shaving steam such as extraction steam or main steam of the large steam turbine 2 to the small steam turbine 6 to drive the small steam turbine 6. The small steam turbine 6 drives the rotating components of the air compressor and the supercharger to rotate under the drive of the peak-shaving steam. On the other hand, the air separation device is connected to the generator 3, and can obtain peak-shaving electricity from the generator 3 through the peak-shaving control module.

[0068] That is, in this embodiment, both the peak-shaving steam and the peak-shaving electricity are used as the power source of the air compressor 5 and the booster 8. The air separation device in this embodiment adopts two driving modes: electric drive and steam drive. The air separation device can use the peak-shaving surplus electricity and peak-shaving surplus steam during the non-peak period of electricity consumption of the power plant, that is, the peak-shaving surplus electricity and peak-shaving surplus steam during the non-peak period of electricity consumption of the power plant are used to provide power for the air separation device.

[0069] Embodiment 4

[0070] like Figure 5 As shown, the overall structure of this embodiment is consistent with that of the third embodiment, and the working method and principle are the same, except that the air compressor 5 and the booster 8 are connected to the thermal power plant or the industrial park or industrial facilities adjacent to the power plant through pipelines. That is, the compressed air generated by the air compression process of the air compressor 5 and the booster 8 can be used as the industrial driving compressed air source for the thermal power plant (such as boiler air supply or instrument or pneumatic valve driving compressed air) or the nearby industrial park.

[0071] On the one hand, the peak-shaving system of the air separation device of the thermal power plant of the present invention effectively utilizes the peak-shaving surplus electricity and heat energy of the thermal power generating set to meet the equipment energy supply of the air separation device, reduces the energy consumption of the external supplementary driving air separation device, avoids resource waste, improves energy utilization, and transforms the modern thermal power plant into a comprehensive factory of electric energy, heat energy, compressed air energy and various air separation gas products; on the other hand, the surplus cold capacity of the cold box in the air separation device cools the air-conditioning circulating water, which is used for air-conditioning refrigeration of the thermal power plant or nearby buildings; furthermore, the compressed air generated by the air compression process in the air separation device can be used as an industrial driving compressed air source for the thermal power generating set or the nearby industrial park; the method also realizes the storage of electric energy in disguise, can supplement the online power of the thermal power plant, and alleviates the problems of power grid balance and peak-valley difference.

[0072] Embodiment 5

[0073] Embodiments 1 to 4 provide two peak-shaving driving modes for the air separation device, one is an electric driving mode, and the other is a peak-shaving steam driving mode.

[0074] A peak shaving method for an air separation device in a thermal power plant, such as Figure 6 The peak-shaving method uses the peak-shaving system described in the above embodiment, and the specific steps of the peak-shaving method are as follows:

[0075] S1: The thermal power plant receives a deep peak load reduction or load increase instruction from the power grid dispatching center. The power it increases or decreases for online power is the peak load P. 调峰 ; Among them, when the amount of electricity on the grid increases, the peak load P 调峰 is negative; when the amount of Internet access decreases, the peak load P 调峰 is positive;

[0076] S2: Select the peak-shaving driving mode of the air separation device. If it is the electric driving mode, execute step S3; if it is the peak-shaving steam driving mode, execute step S4;

[0077] S3: The peak load control module adjusts the power consumption of the air separation device so that it can respond to the peak load instruction of the power grid in time. The specific formula is:

[0078] P 调峰 =P 空耗’ -P 空耗0 , where: P 空耗0 is the power consumption of the air separation unit before peak load regulation, P 空耗’ is the power consumption of the air separation unit after peak load regulation;

[0079] S4: The peak-shaving system includes a steam supply regulating valve, which regulates the peak-shaving steam source flow rate F supplied to the air separation device. 调峰 ;

[0080] According to the situation of the peak-shaving system, select the optimal peak-shaving steam source. The flow rate F of this peak-shaving steam source is 调峰 and peak load P 调峰 The relationship formula is:

[0081] F 调峰 =0.278*P 调峰 / (△H 剩余 *η 大汽机 *η e )

[0082] Where: P 调峰 is the peak load, in kW;

[0083] △H 剩余 It is the residual enthalpy difference between the steam extracted from the large steam turbine and the exhaust enthalpy value, in kJ / kg. When the steam is extracted before reheating, the residual enthalpy difference includes the enthalpy rise caused by the reheater.

[0084] η大汽机 is the relative internal efficiency of the large steam turbine;

[0085] η e is the generator efficiency;

[0086] S5: According to the calculation result of S4, F 调峰 , adjust the opening of the steam supply regulating valve to provide peak steam source flow F 调峰 , so that thermal power units can respond to grid peak load regulation instructions.

[0087] The calculation formula of S4 is a rough calculation formula. According to the source of peak-shaving steam, it can be divided into the following cases for specific calculation:

[0088] (1) The peak-shaving steam comes from the main steam.

[0089] F 调峰 =0.278*P 调峰 / {[(H 0高 -H 高排 )*η 高 +(H 0中 -H 中排 )*η 中 +(H 0低 -H 低排 )*η 低 ]*η e}

[0090] (2) If the peak-shaving steam comes from the high-pressure cylinder extraction or exhaust steam,

[0091] F 调峰 =0.278*P 调峰 / {[(H 高抽或高排 -H 高排 )*η 高 +(H 0中 -H 中排 )*η 中 +(H 0低 -H 低排 )*η 低 ]*η e}

[0092] (3) If the peak-shaving steam comes from the intermediate pressure cylinder inlet, extraction or exhaust steam, then

[0093] F 调峰 =0.278*P 调峰 / {[(H 0中或中抽或中排 -H 中排 )*η 中 +(H 0低 -H 低排 )*η 低 ]*η e}

[0094] In the above formula:

[0095] F 调峰 is the peak steam volume, unit: kg / h;

[0096] P 调峰 is the peak load, in kW;

[0097] H 0高 is the main steam enthalpy, unit is kJ / kg;

[0098] H 高排 is the enthalpy of high-pressure cylinder exhaust steam, unit is kJ / kg;

[0099] η 高 is the internal efficiency of the high-pressure cylinder steam turbine;

[0100] H 0中 is the steam enthalpy of the intermediate pressure cylinder, in kJ / kg;

[0101] H 中排 is the exhaust steam enthalpy of the intermediate pressure cylinder, in kJ / kg;

[0102] η 中 is the efficiency of the medium pressure cylinder steam turbine;

[0103] H 0低 is the steam enthalpy of the low-pressure cylinder inlet, in kJ / kg;

[0104] H 低排 is the exhaust steam enthalpy of the low-pressure cylinder, in kJ / kg;

[0105] η 低 is the internal efficiency of the low-pressure cylinder steam turbine;

[0106] η e is the generator efficiency.

[0107] In the description of this application, "install", "connect", "connect", "fix" and the like should be understood in a broad sense. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or a connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0108] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0109] Those skilled in the art should understand that although the embodiments disclosed in the embodiments of the invention are as above, the contents described are only embodiments adopted to facilitate understanding of the invention and are not intended to limit the embodiments of the invention. Any person skilled in the art of the embodiments of the invention may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the invention, but the scope of patent protection of the embodiments of the invention shall still be subject to the scope defined by the attached claims.

Claims

1. A peak-shaving method for an air separation device in a thermal power plant, using a peak-shaving system, wherein the peak-shaving system comprises a thermal power plant generator set, wherein the thermal power plant generator set comprises a large steam turbine (2), a generator (3) and a peak-shaving control module, wherein the peak-shaving control module receives a peak-shaving instruction from a power grid dispatching center; the air separation device is connected to a steam pipeline of the generator (3) and / or the thermal power plant generator set, and the peak-shaving control module can transfer the power of the generator (3) and / or the steam of the thermal power plant group to the air separation device to drive the air separation device, characterized in that: The specific steps of the peak shaving method are as follows: S1: The thermal power plant receives a deep peak load reduction or load increase instruction from the power grid dispatching center. The power it increases or decreases for online power is the peak load P. 调峰 ; S2: Select the peak-shaving driving mode of the air separation device. If it is the electric driving mode, execute step S3; if it is the peak-shaving steam driving mode, execute step S4; S3: The peak load control module adjusts the power consumption of the air separation device so that it can respond to the peak load instruction of the power grid in time. The specific formula is: P 调峰 =P 空耗’ -P 空耗0 , where: P 空耗0 is the power consumption of the air separation unit before peak load regulation, P 空耗’ is the power consumption of the air separation unit after peak load regulation; S4: The peak-shaving system includes a steam supply regulating valve, which regulates the peak-shaving steam source flow rate F supplied to the air separation device. 调峰 ; According to the situation of the peak-shaving system, select the optimal peak-shaving steam source. The flow rate F of this peak-shaving steam source is 调峰 and peak load P 调峰 The relationship formula is: F 调峰 =0.278*P 调峰 / (△H 剩余 *or 大汽机 *or e ); Where: P 调峰 is the peak load, in kW; △H 剩余 It is the residual enthalpy difference between the steam extracted from the large steam turbine and the exhaust enthalpy value, in kJ / kg. When the steam is extracted before reheating, the residual enthalpy difference includes the enthalpy rise caused by the reheater. η 大汽机 is the relative internal efficiency of the large steam turbine; η e is the generator efficiency; S5: According to the calculation result of S4, F 调峰 , adjust the opening of the steam supply regulating valve to provide peak steam source flow F 调峰 , so that thermal power units can respond to grid peak load regulation instructions.

2. The peak shaving method of the air separation device in a thermal power plant according to claim 1, characterized in that: The driving steam of the air separation device comes from the steam extraction pipeline of the large steam turbine (2) of the power plant generator set or the main steam pipeline of the power plant.

3. The peak shaving method of the air separation device in a thermal power plant according to claim 2, characterized in that: The peak shaving system comprises a small steam turbine (6) of a steam-driven air separation device, wherein the small steam turbine (6) is connected to a steam extraction pipeline of a large steam turbine (2) of a thermal power generating set or a main steam pipeline of a power plant; the peak shaving control module is capable of controlling the amount of steam supplied to the small steam turbine (6) by the peak shaving steam to drive the small steam turbine (6); the small steam turbine (6) performs work under the drive of the peak shaving steam to drive the air separation device.

4. The peak load regulation method of the air separation device in a thermal power plant according to claim 3, characterized in that: The air separation device comprises a compressor; the small steam turbine (6) is connected to the compressor via a coupling to drive the compressor.

5. The peak load regulation method of the air separation device in a thermal power plant according to claim 4, characterized in that: The compressor is an air compressor (5) and / or a booster (8).

6. The peak load regulation method for air separation device in thermal power plant according to any one of claims 1 to 4, characterized in that: The air separation device comprises a compressor; the generator (3) is connected to the compressor to drive the compressor with electricity.

7. The peak load regulation method of the air separation device in a thermal power plant according to claim 6, characterized in that: The compressor is at least one of an air compressor (5), a booster (8), and a product booster.

8. The peak load regulation method of the air separation device in a thermal power plant according to claim 7, characterized in that: The compressed air generated in the air compression process of the air separation device is used as an industrial driving compressed air source for a thermal power plant or a nearby industrial park.

9. The peak load regulation method of the air separation device in a thermal power plant according to claim 7, characterized in that: The product booster comprises an oxygen compressor (13) and / or a nitrogen compressor (14); the air separation device comprises a precooling system (7) and a cold box (12), the precooling system (7) is connected to an air compressor (5), and the cold box (12) is connected to the oxygen compressor (13) and / or the nitrogen compressor (14); the precooling system (7) and / or the cold box (12) are connected to a refrigeration circulating water pipeline of an external refrigeration device of a thermal power plant, and are capable of transferring surplus cooling capacity to the refrigeration circulating water pipeline of the external refrigeration device; the air separation device comprises a low-temperature liquid phase storage tank or storage tank for storing the final air separation product.

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