Application of FlywheelEnergy Storage Technology in Industrial Energy Saving

I. National Policies

Accordingto the "Notice on Carrying Out the 2019 National Industrial Energy-savingTechnical Equipment Recommendations and" Energy Efficiency Star"Product Evaluation Work" issued by the Ministry of Industry andInformation Technology in 2019, the declared industrial energy-savingtechnology can be widely used in iron and steel, petrochemical, chemical, buildingmaterials, non-ferrous metals, machinery, light industry, textile andelectronics industries; Key collection process industrial energy-savingtransformation, key energy-using equipment system energy-saving (industrialboilers and kilns, motor systems, transformers, etc.), renewable energy andresidual energy utilization,Industrial Park energy system optimization (energycascade utilization, microgrid, energy storage, insulation, sealing, etc.),energy information control, coal efficient and clean use technology.

II.Application Statements

Forthe purpose of promoting energy-saving, environmental protection, and improvingunit performance, prolonging unit service life and reducing maintenance cost,etc., which have been concerned by many industries. For example, forpetrochemicals, HHE/ Bomay Electric Industry Co., Ltd. jointly developed energyrecovery + flywheel energy storage + fuel/gas generators technology to solvethe problems of high-power load shock, high energy consumption of diesel/gasgenerators, black smoke emission and high noise. Thus, the maintenance cost ofthe equipment is reduced (the excessive load impact caused by the increase offuel consumption and easy to cause diesel engine / gas unit, dropping, leaking,carbon accumulation and other serious problems, easy fault, large amount ofmaintenance;). After the expert group review, the project directly forcustomers to reduce the number of gas generators, greatly reduce the initialinvestment costs, technology to reach the international advanced level.

Flywheel energy storage site of CNPC (Karamay, Xinjiang)drilling platform

Thereare similar problems in iron and steel industry, and several typical impactloads in steelworks include: Medium Frequency Furnace , Ladle Furnace, ElectricArc Furnace, Rolling Mill, Oxygen Air Compressor, among which the loadcharacteristics of Ladle Furnace, Electric Arc Furnace and Oxygen Air Compressorare similar, so the load characteristics of Medium Frequency Furnace, Electric ArcFurnace and   Rolling Mill are analyzedemphatically.

The mediumfrequency furnace is the largest capacity load in the steelworks, and thesingle capacity accounts for 15% of the total unit capacity. In order to reducethe impact of the start and stop of the medium frequency furnace, it is usuallymodified to add and reduce the load.

The electricarc furnace belongs to a single large capacity load in a steelworks, usuallyaccounting for about 5% of the total unit capacity. Because the powerfluctuation of its starting and stopping is within the adjustment range of theprimary frequency modulation of the unit, the modification of linear loadaddition and reduction will not be carried out.

-- Rollingmill is the most frequent impact load in steelworks, its impact duration isabout 10 s, the interval between multiple shock is about 10 s, the impact powerof one rolling line is about 5% of the total unit capacity.

According tothe above three parts of the steel industry, the steel industry can beinitially divided into the following two categories:

1.   The power fluctuation of the impact load isborne by the large power grid. Because the large power grid has enough rotatingreserve, it is not easy to cause the frequency fluctuation problem. But most ofthe daily work of steel mills only use about 30% of the total capacity, so theannual need to pay the grid company a high reserve capacity fee, increasedproduction costs.

2.   In order to avoid the problem of systemfrequency stability caused by impact load, steel mills need to build self-ownedpower plants with large capacity, which leads to high investment cost.

In order tosave energy and reduce investment cost, and also according to the operationcharacteristics of iron and steel industry itself, to smooth the rapid changeof impact load power in the power grid system of steelworks , to smooth thefrequency fluctuation of the system, to rationally configure the capacity of flywheelenergy storage system , to adopt droop control mode to deal with the load ofrolling mill with high impact frequency. The common load (load switch control)with reasonable capacity of the system is configured, and the mirror powercontrol mode is adopted to deal with the load of intermediate frequency furnaceand electric arc furnace with low impact frequency.

In summary,the addtion of flywheel energy storage system can directly reduce the capacitycost and the installed capacity of self-provided power plant, and the projectcost can be recovered about 3.5 years by optimizing the operation scheme.

III. Introduction of Flywheel EnergyStorage

The magneticlevitation flywheel energy storage device is a high efficiency conversionsystem between electric energy and kinetic energy. The system adopts magneticlevitation technology. The flywheel rotor works in a vacuum room and operatesin an no air resistance,This design structure reduces energy loss duringoperation and increases the speed of the flywheel . When charging, it isequivalent to an motor, converting electric energy into kinetic energy, rotationalspeed up to 30000 rpm , as energy for storage; when discharging, it isequivalent to the generator, using the inertia of speed drop to convert kineticenergy into electric energy to release .

Mechanical Structure of Flywheel Noumenon

High powerdensity, fast charge and discharge: HHE has 300 kW/2kWh flywheel matureproducts, which means "charge and discharge rate" can reach 150 C,millisecond response speed;

Long servicelife: cycle charge and discharge times up to ten million times, theoreticallife more than 20 years, and energy storage capacity will not decrease with theincrease of charge and discharge times;

Wideoperating temperature range: no strict requirements for ambient temperature,the flywheel body need not build air-conditioning room;

High energyconversion efficiency: the conversion efficiency between the kinetic energy ofelectric energy is higher than 95%, and the comprehensive efficiency of energystorage system is about 90%;

Low loss, lowmaintenance: magnetic levitation and vacuum environment make the mechanicalloss can be ignored, flywheel noumenon need not be maintained, the whole system maintenance period is long;

Accurately measure and control: flywheelenergy storage can accurately measure the rotor speed so as to accuratelycalculate the "residual power" to achieve accurate control;

Safety andenvironmental protection: flywheel energy storage more than 98% of thematerials are steel, no chemical release, no chemical explosion and othersafety risks, from the production to the application of the entire link is environmentallyfriendly;

Large-scalemanufacturing costs dropped significantly: flywheel is mainly made of steel,large-scale manufacturing costs dropped sharply, infinitely close to steelcosts;

High residualvalue :" waste flywheel battery "can be directly recycled, recoveryprocess is simple, high residual value.

IV. Company Profile

BeijingHonghui Energy Development Co., Ltd., led by members of the National FirstPrize for Technological Invention, has successfully developed high-powermagnetic levitation flywheel energy storage technology and products withindependent intellectual property rights through years of dedicated researchand unremitting efforts.It is applied in the civil field and has achievedlarge-scale commercial manufacturing of magnetic levitation flywheels, and iscommitted to providing comprehensive solutions for energy saving, energystorage and power quality improvement for customers in different fields withthis technology as the core.

The HHEseries of high performance energy storage flywheel products developed by thecompany can be widely used in the fields of rail transit braking energyrecovery, UPS millisecond uninterruptible power supply, port terminal gantrycrane energy saving and life extension, and microgrid, civil air defenseengineering, wind and solar energy storage power station and so on.

In additionto supply flywheel products, HHE takes advantage of its own technology, fundsand management advantages to provide comprehensive contract energy management,energy conservation transformation, clean energy development and othercomprehensive system solutions and derivative services according to thecharacteristics and needs of the customer .

Because ofthe environmental friendliness of flywheel energy storage   from manufacturing, operation to recyclinglife cycle, and the characteristics of high efficiency energy recovery, realuninterrupted and long life, HHE will lead the strategic direction of energystorage application in the future, and become an internationally respectedenergy saving and environmental protection enterprise.Together with experts tocommit to popularizing and applying flywheel energy storage technology in moreindustries.