A kind of supercritical air energy storage system of novel flow process
Technical field
The present invention relates to that the supercritical air energy storage of energy storage technical field, particularly a kind of novel flow process/releasing can system.
Background technique
The electric power energy storage technology is the important means of adjusting at present the electrical network peak valley, improving power system economy and stability, being one of extensive most important bottleneck that utilizes of unstable, the step renewable energy sources of restriction, also is the key technology of distributed energy and intelligent grid.At present existing electric power energy storage technology comprises pumped storage power station, pressurized air, storage battery, superconduction magnetic energy, flywheel and electric capacity etc.But owing to reasons such as capacity, energy storage cycle, energy density, efficiency for charge-discharge, life-span, operating cost, environmental protection, only draw water two kinds of power station and the pressurized air that in the large scale business system, have moved at present.
Conventional compression air energy-storage system is based on a kind of energy-storage system of gas turbine technology exploitation.At low power consumption, air pressure contractd to be stored in the gas storage chamber, and making electric energy conversion is that the interior of air can store; In peak of power consumption, high-pressure air discharges from gas storage chamber, enters gas-turbine combustion chamber and burns together with fuel, then drives turbine power generation.Compressed-air energy-storage system has that stored energy capacitance is large, the energy storage cycle is long, efficient is high (50%~70%) and the advantage such as specific investment cost less, but, conventional compression air energy-storage system is not an independently technology, it must support the use with turbine power plant, can not be fit to other types, such as power stations such as coal fired power plant, nuclear power station, wind energy and solar energy, be not suitable for especially China take coal fired power generation as main, do not advocate the energy strategy of gas fuel generating.And, compressed-air energy-storage system still relies on combustion of fossil fuels thermal source is provided, face on the one hand that fossil fuel is petered out and the threat of rise in price, its burning still produces the pollutants such as nitride, sulphide and carbon dioxide on the other hand, does not meet green (zero-emission), reproducible energy development requirement.More fatal is, because energy storage density is low, compressed-air energy-storage system also needs specific geographical conditions to build large-scale gas storage chamber, such as rock cavity, Yan Dong, abandoned mine etc., thereby has greatly limited the application area of compressed-air energy-storage system.
The subject matter that faces for solving conventional compression air energy-storage system, particularly to the Dependence Problem of gas turbine, recent years Chinese scholars carried out respectively ground compressed-air energy-storage system (SVCAES), with the compressed-air energy-storage system (AACAES) of backheat, air vapor combined cycle compressed-air energy-storage system (CASH) etc., make compressed-air energy-storage system substantially can break away from the combustion of fossil fuel thermal source.But owing to do not adopt the fossil fuel thermal source, the energy density of compressed-air energy-storage system is lower, has more highlighted large-scale gas storage chamber is relied on, and efficient is also not high enough simultaneously, must find rational solution, just can make the air energy-storage system obtain more extensive and effectively utilize.
In recent years, Institute of Engineering Thernophysics, Academia Sinica has developed supercritical air energy storage system, and it utilizes the character under the super critical condition of air, solves the major technique bottleneck that the energy storage of conventional compression air exists.But large occupation of land is many, efficient is not high problem that still there is the reservoir vessel volume in supercritical air energy storage system, the irreversible loss of single dependence throttle valve liquefaction is larger, system flow is reasonable not, and energy utilizes insufficient, causes system effectiveness lower (approximately only having about 65%).
The present invention proposes a kind of supercritical air energy storage of novel flow process/release can system, further promotes the performance of air energy-storage system, reduces simultaneously cost.
Summary of the invention
The objective of the invention is to disclose a kind of supercritical air energy storage of novel flow process/release can system, and it utilizes the system flow innovation, promotes the supercritical air energy storage system performance, is suitable for all kinds power station and electrical network energy storage.After using the combination of decompressor or decompressor and throttle valve, can effectively utilize the pressure energy of gas, realize the comprehensive cascade utilization of high-grade energy, be conducive to improve the system liquid rate, break away from extraneous cold and replenish, thereby obviously improve system effectiveness.
For achieving the above object, technical solution of the present invention is:
The supercritical air energy storage of novel flow process/release and system to comprise compressor bank, accumulation of heat/heat exchanger package, cold-storage/heat exchanger package, expansion unit, low-temperature storage tank, valve, cryopump, turbines, generator, driver element and many pipelines.One of remarkable difference of it and supercritical air energy storage system is to replace throttle valve with the combination of decompressor or decompressor and throttle valve, decompressor is by gear-box or coupling drive compression machine, remarkable increase system efficiency, application by accumulation of heat and cold-storage heat-exchanger group reduces materials consumption, reduces system cost.Another is significantly distinguished and is that accumulation of heat/heat exchanger package comprises two accumulation of heat/heat exchangers that are under the different working pressures at least, and store and take from heat cold between compression system, and for turbines; And cold-storage/heat exchanger package comprises two cold-storage/heat exchangers that are under the different working pressures at least, stores the cold of energy storage and exoergic process, by the different pressures design, can economical with materials, and reduce system cost.
Compressor bank of the present invention comprises at least two compressors, mutually connects or is integrated into whole multistage compressor, and at least one compressor is directly driven by the expansion unit, to improve system effectiveness.Enter or directly enter behind the outlet of expansion unit afterbody access cold-storage/heat exchanger throttle valve a little decrease temperature and pressure can realize liquefaction.Compressor and decompressor all can be piston type, centrifugal, axial flow and combined type, its type and number of units viewing system parameter and decide; Decompressor and compressor can be designed to coaxial combination, and also can connect by gearbox provides compressor power, thereby improves system effectiveness and Economy.System layout is as follows:
Each stage compressor links to each other with accumulation of heat/heat exchanger package respectively through pipeline; Design according to the pressure coupling can reduce materials consumption, reduces system cost.High-pressure air after the store compressed heat enters decompressor or is introduced into decompressor after entering the cooling of cold-storage heat-exchanger group through pipeline, pass through again throttle valve (also can cancel) after the decrease temperature and pressure and enter low-temperature storage tank through pipeline, be provided with valve, at least one cryopump in pipeline, valve is positioned at the cryopump upstream; Accumulation of heat/heat exchanger combination superheater interlinks with turbines respectively through pipeline.
Its workflow is: during energy storage, utilize drive unit drives combined type compression unit, to supercritical state, every grade the heat of compression is recovered and is stored in accumulation of heat/heat exchanger with a certain amount of air compressing; Then the air of certain parameter enters in cold-storage/heat exchanger package and cools off, pass through again expansion unit expansion decrease temperature and pressure after, further by throttle valve or directly change liquid air into by decompressor and enter low-temperature storage tank storage; When releasing energy, cryopump liquid towards air pressurized is to certain pressure, the high-pressure liquid air is warming up to supercritical state and reclaims cold energy in cold-storage/heat exchanger package, absorbing the heat of compression in accumulation of heat/heat exchanger package and superheater further heats up air, then enter the turbines acting, drive the generator generating.
Described air energy-storage system, its described driver element is the motor that drives with electrical network or conventional power plant trough-electricity, nuclear power, wind-powered electricity generation, solar electrical energy generation, biomass power generation, water power or tidal power generation one or more power supplys wherein.
Described air energy-storage system, its thermal energy storage process is rationed the power supply or the quality of power supply is enabled when not meeting internet access request in electric power low ebb, renewable energy sources; Exoergic process is enabled when peak of power consumption, electric power accident, renewable energy power generation fluctuation.
Described air energy-storage system, its compression process comprises at least one decompressor, is used for making the pressurized air decrease temperature and pressure to be convenient to liquefaction and recovery expansion work, improves system effectiveness.
Described air energy-storage system, the medium that stores in the low-temperature storage tank is liquid air or other liquefiable working medium, when working medium is not air, the air bag that the low pressure compressor import is connected with low-pressure turbine by a constant voltage transfiguration connects, the realization working medium circulation utilizes, and liquid refrigerant stores under normal pressure or band certain pressure situation.
Described air energy-storage system, its described accumulation of heat superheater is provided with pipeline, and this pipeline and extraneous thermal source interlink, and extraneous thermal source can be solar thermal collector, industrial exhaust heat and all kinds of used heat.Described waste heat, used heat are waste heat, the used heat of power plant, cement industry, iron and steel metallurgical industry, chemical industry; Waste heat, used heat can be stored in accumulation of heat/heat exchanger, also can be stored in the special-purpose accumulation of heat superheater.
Described air energy-storage system, its described compressor bank; When being multiple compressors, multiple compressors is coaxial series connection form or split axle parallel form; In the parallel form, each split axle and main driving axle are dynamically connected; The exhaust of each stage compressor all cools through corresponding accumulation of heat/heat exchanger.
Described air energy-storage system, its described turbines, the final stage gas turbine exhaust is near normal pressure; When being many turbo machines, many turbo machines are coaxial series connection form or split axle parallel form; In the parallel form, each split axle and main driving axle are dynamically connected; Corresponding accumulation of heat/heat exchanger heat temperature raising is all passed through first in the air inlet of each stage turbine, or continues to heat up through the accumulation of heat superheater.
Described air energy-storage system, its described compressor and decompressor all can be piston type, centrifugal, axial flow, screw type or combined type.
Described air energy-storage system, it is described when multiple compressors, many decompressors, and multiple compressors, many decompressors are distributed on a live axle or the many live axles, connect by gearbox.
Described air energy-storage system, the accumulation of heat form of its described accumulation of heat/heat exchanger package is one or more that sensible heat, latent heat or chemical reaction are pined for; The heat storage medium that adopts is water, paraffin, bio-oil, mineral-type crystalline hydrate salt, fuse salt, metal and alloy, organic fatty acid, stone, rock or concrete, and heat storage medium is stored in the thermally insulated container.
Described air energy-storage system, its described cold-storage/heat exchanger, it is Kelvin temperature unit that air is cooled to 81K-150K(K), be a kind of or combination in sensible heat cold-storage or the solid-liquid phase change cold-storage; The sensible heat cool storage medium that adopts is one or more in sealing ice hockey, sandstone, concrete, aluminium strip dish or other metallics; The solid-liquid phase change cool storage medium is ammonia and the aqueous solution, salts solution, alkanes, olefines material and the compound thereof of solid-liquid phase change temperature between 81K~273K, one or more in alcohols and the aqueous solution thereof, and cool storage medium is stored in the thermally insulated container; Air in cold-storage/heat exchanger with cool storage medium direct contact heat transfer or non-direct contact heat transfer; During energy storage, cold-storage/heat exchanger further cools off air is convenient to liquefaction, and when releasing energy, cold-storage/heat exchanger reclaims and store the cold in the high-pressure liquid atmosphere temperature rising process.
Described air energy-storage system, its described low-temperature storage tank is Dewar storage tank or low temperature storing tank, liquid air stores under atmospheric pressure or under pressure power situation.
Described air energy-storage system during its energy storage, is regulated energy storage capacity by control first order compressor air inflow.Described air energy-storage system, its described control first order compressor air inflow is by regulating compressor load, valve opening, driving rotating speed, start-stop Partial shrinkage machine or regulating the control that pressure ratio realizes air inflow.When it releases energy, regulate generating capacity by control liquid air flow.
The invention has the advantages that: the decompressor that replaces throttle valve is coaxial or by the interconnected transmission of gear-box with compressor, energy storage efficiency than supercritical air system improve, system cost reduction about 10%, have wide prospect of the application.
Description of drawings
Fig. 1 is supercritical air energy storage system embodiment 1 structural representation of novel flow process of the present invention;
Fig. 2 is supercritical air energy storage system embodiment 2 structural representations of novel flow process of the present invention.
Embodiment
For making purpose of the present invention, technological scheme and advantage clearer, referring to the accompanying drawing embodiment that develops simultaneously, the present invention is described in more detail.
The supercritical air energy storage system of novel flow process of the present invention, adopt power station low ebb (at a low price) electric energy with air compressing to supercritical state (simultaneously store compressed heat), then utilizing the expansion unit to make the air cooling-down step-down reclaim simultaneously expansion work raises the efficiency, decompressor is coaxial or interconnected by gear-box with compressor in this process, help to raise the efficiency the reduction cost, utilize the cold energy of having stored with pressure-air cooling, liquefaction and storage (energy storage); In peak of power consumption, the liquid air pressurization is absorbed heat to supercritical state (cold energy in the liquid air is recovered storage simultaneously), and driving generator generating (releasing energy) by turbines after the heat of compression of further absorption storage, some industrial waste heats can be recovered to improve system effectiveness in this process.
Embodiment:
Fig. 1 is the supercritical air energy storage system embodiment 1 of novel flow process of the present invention.Comprise compressor units C1, C2, accumulation of heat/heat exchanger package 2,5, expansion unit E1, E2, cold-storage/heat exchanger package 8,10, low-temperature storage tank 15, valve 13,17, cryopump 19, turbines T1, T2, generator 29, drive motor 32, pipeline A, 1,3,4,6,7,9,11,12,14,16,18,20,21,22,23,24,25,27,28 etc.
Drive motor 32 is affixed with the total transmission shaft of compressor bank C1, C2, and generator 29 is affixed with the total transmission shaft of turbines T1, T2.Compressor bank C1, C2 link to each other with accumulation of heat/heat exchanger package 2,5 respectively through pipeline 1,3,4,6.Low pressure compressor C1 entrance connects air.Through the supercritical air of accumulation of heat/heat exchanger 5 through pipeline 6,7,9,11 by cold-storage/heat exchanger package 8,10 and expansion unit E1, E2 decrease temperature and pressure, again through throttle valve 13 liquefaction.Accumulation of heat/heat exchanger package 2,5 links to each other with expansion unit T1, T2 respectively through pipeline 22,23,24,25,27 with accumulation of heat superheater 26, and the gas outlet of low-pressure turbine T1 leads to atmosphere.Accumulation of heat superheater 26 through pipeline 30,31 and extraneous thermal source interlink.
During energy storage, utilize driver element 32 drive compression unit C1, C2, to supercritical state, every grade the heat of compression is recovered and is stored in accumulation of heat/heat exchanger package 2,5 the corresponding tank body with a certain amount of air compressing; Then the air of certain parameter enters cooling in cold-storage/heat exchanger package 8,10, after passing through again expansion unit E1, E2 expansion decrease temperature and pressure, further through the cold-storage heat-exchanger group or directly by throttle valve 13 or directly change liquid air into by decompressor and enter low-temperature storage tank storage 15; When releasing energy, cryopump 19 liquid towards air pressurized are to certain pressure, the high-pressure liquid air is warming up to supercritical state and reclaims cold energy in cold-storage/heat exchanger package 8,10, accumulation of heat/heat exchanger package 2,5 and superheater 26 in absorb the heat of compression air further heated up, then enter turbines T1, T2 acting, drive generator 29 generatings.
Fig. 2 is the supercritical air energy storage system embodiment 2 of novel flow process of the present invention.Its structure is basic identical with embodiment 1, but decompressor all is positioned at before cold-storage/heat exchanger 8,10, enters through the Cryogenic air behind the expansion unit to enter throttle valve 13 after cold-storage/heat exchanger package cooling and further liquefy.Other workflows are similar with embodiment 1.
The above only is preferred embodiment of the present invention, does not therefore limit protection scope of the present invention.