WO2015010486A1

WO2015010486A1 - Power control method of aluminum electrolyzing system for non-grid-connected multi-energy collaborative power supply

Info

Publication number: WO2015010486A1
Application number: PCT/CN2014/076778
Authority: WO
Inventors: 顾为东
Original assignee: Gu Weidong
Priority date: 2013-07-24
Filing date: 2014-05-05
Publication date: 2015-01-29
Also published as: CN103427424A; CN103427424B

Abstract

A power control method of an aluminum electrolyzing system for non-grid-connected multi-energy collaborative power supply, the aluminum electrolyzing system comprising an aluminum electrolyzing device, a wind power generation device and a solar power generation device; the wind power generation device and the solar power generation device supply power for the aluminum electrolyzing device in a non-grid-connected manner, and the waste heat generated by the aluminum electrolyzing device is recycled to generate power to be supplied to an aluminum electrolytic cell; during the day, the public grid supplies the minimum power required by the aluminum electrolytic cell to operate with heat preservation, the power generated by the wind power generation device and the concentrating solar power generation device being supplemental; during the night, the limit is cancelled on public grid power supply to the aluminum electrolyzing device. The power control method can adapt to the fluctuation of wind power generation and solar power generation, improve economic returns of enterprises by fully utilizing the peak/valley electricity price difference of the pubic grid, and facilitate peak load regulation in the public grid so as to reduce the difficulty in peak load regulation caused by the great difference between peak load and valley load.

Description

Power control method for electrolytic aluminum system with non-grid-connected multi-energy coordinated power supply

Technical field

The invention relates to a power control method for an electrolytic aluminum system which is not connected to the grid and multi-energy coordinated power supply, and belongs to the technical field of electrolytic aluminum.

Background technique

The utility grids in most countries in the world implement peak-to-valley time-sharing electricity prices, and set price levels according to the load level of the power grid. This will help users to cut peaks and fill valleys and improve the utilization efficiency of public power grids. For the users of the peak-to-valley price of the peaks and valleys, the electricity price ratio of the peak period and the valley period is generally in the range of 1. 1 to 4.1.

In many countries, the utility grid is dominated by nuclear power and coal-fired power. The power supply structure dominated by nuclear power and coal-fired power is seriously lacking in peak-shaving power supply and cannot be deeply peak-regulated. However, with urbanization and industrialization, the annual power load of the power grid increases. The peak-to-valley difference will exceed 50%, so there is considerable peaking pressure.

As a clean, non-polluting renewable energy source, wind energy is considered an important part of the world's energy strategy. At present, the application of large-scale wind farms in the world is mainly based on wind power integration. The utilization of wind energy is mainly carried out according to the route of “wind turbine-generator-grid-user (load)”, where the grid is the load and user of wind power. Power supply. However, due to the instability and fluctuation characteristics of wind power, large-scale wind power grids still have technical obstacles that are difficult to overcome at this stage. It is difficult to overcome the contribution of wind power to the public power grid by more than 10%. At the same time, wind power grids have put forward requirements for wind turbines to meet the stability, voltage regulation and stability of the power grid, which has greatly increased the cost of wind turbine manufacturing and wind power, which limits the large-scale application of wind power.

As a clean, non-polluting renewable energy source, solar energy is considered an important part of the world's energy strategy. Solar power generation is a way to replace conventional energy and is one of the focuses of scientists and governments around the world.

With the rapid expansion of electrolytic aluminum scale in recent years, facing the high cost of electricity consumption, how to reduce the energy consumption of power supply system equipment has become a common problem faced by many industries. For example, in 2008, China's electrolytic aluminum production reached 13.17 million tons. According to the current production level of electrolytic aluminum in the country, the DC power consumption per ton of aluminum produced is about 13 200 kWh, and the DC power consumption of the whole industry is about 173.8 billion kWh. About 7 percent of China's electricity consumption is a typical high-energy industry. Due to the large scale of large-capacity aluminum electrolytic cells, the huge power load is concentrated in one production series, and any power fluctuation generated by aluminum electrolytic series production will have a greater impact on the power grid. Therefore, make full use of the existing wind and solar energy, and make full use of the peak-to-valley difference of the power grid (such as the daytime (communication grid peak hours) of large-scale power enterprises in coastal areas of Jiangsu Province, China, the electricity price is 1. 05 yuan / kWh, night (public grid valley) Time period) is reduced to 0. 27 yuan / kWh, and improving the economic efficiency (profit) of the enterprise has become an urgent problem to be solved.

The applicant's search found that the Chinese patent publication No. CN 102943287A discloses a wind-solar complementary electrolytic aluminum device. The wind-solar complementary electrolytic aluminum device adopts a combination of wind power, solar thermal power generation and grid electricity to supply electric energy to the electrolytic aluminum, and the wind energy is complemented by the residual heat generated by the solar energy and the aluminum electrolytic tank in a non-grid form. However, like the traditional electrolytic aluminum device, the power fluctuation generated by the wind-solar complementary electrolytic aluminum device will have a greater impact on the power grid, and the peak-to-valley difference of the power grid cannot be fully utilized to improve the economic efficiency (profit) of the enterprise, and the high efficiency cannot be solved. The impact of power fluctuations on the load of the electrolytic aluminum unit on the utility grid.

Summary of the invention

The technical problem solved by the invention is: Proposed a power control method for an electrolytic aluminum system that is not connected to the grid and multi-energy collaboratively powered, the method can adapt to the fluctuation of wind power and solar power generation, greatly reduce the production cost, and can fully utilize the peak of the power grid The valley difference improves the economic efficiency of the enterprise, and it can assist the power grid to peak the peak, and reduce the peaking difficulty caused by the difference between the peak load and the low valley load.

In order to solve the above technical problem, the technical solution proposed by the present invention is: a power control method for an electrolytic aluminum system that is not powered by a grid-connected multi-energy, and the electrolytic aluminum system includes an electrolytic aluminum device, a wind power generation device, and a solar power generation device. The electrolytic aluminum device is provided with an aluminum electrolytic cell; the wind power generating device and the solar power generating device supply power to the electrolytic aluminum device in a non-grid manner, and the waste heat emitted by the electrolytic aluminum device is recovered to generate electricity and supply aluminum. Electrolytic tank; when the utility grid is in a peak period, the utility grid supplies power to the electrolytic aluminum device according to the minimum amount of electricity required for the thermal operation of the electrolytic aluminum device, and the amount of electricity generated by the wind power generation device and the solar concentrating power generation device is Supplementary; when the utility grid is in the valley period, the utility grid cancels the limitation of supplying power to the electrolytic aluminum device according to the minimum amount of electricity required for the electrolytic aluminum device to operate for insulation.

The improvement of the above technical solution is: the solar power generation device is a solar concentrating power generation device, and the waste heat emitted by the electrolytic aluminum device is transmitted to the tubular receiver of the solar power generation device through the pipeline through the heat conduction medium, so that the solar power generation device can be used Waste heat power generation.

Preferably, the minimum amount of electricity required for the operation of the electrolytic aluminum device for heat preservation is the amount of power required to maintain the aluminum electrolytic cell of the electrolytic aluminum device only when the electrolytic aluminum liquid is kept at 860-980 ° C when the residual heat is not recovered. . Preferably, the heat transfer medium is a molten salt or a heat transfer oil.

The beneficial effects brought by the invention are:

1) The power control method of the non-integrated multi-energy coordinated power supply electrolytic aluminum system of the invention, the solar power generation device and the wind power generation device all adopt the non-grid connection mode to supply power to the electrolytic aluminum system, and can adapt to large-scale wind power and solar power generation. Fluctuating characteristics; The present invention makes full use of the peak-to-valley electricity price difference of the utility grid (for example, during the daytime (public grid peak hours) electricity price of large-scale power enterprises in Jiangsu coastal areas, the electricity price is 1. 05 yuan / kWh, and at night (public grid period) 0. 27 yuan / kW), during the daytime aluminum electrolytic cell insulation operation, supplemented by wind power and solar power; at night, mainly using wind power, waste heat power generation and grid power to make the aluminum electrolysis tank work at full load, thus increasing the economic benefits of the enterprise .

2) The power control method of the non-integrated multi-energy coordinated power supply electrolytic aluminum system of the invention fully utilizes the peak-to-valley price difference of the utility grid to greatly increase the economic benefit of the enterprise, and also has the function of the night pumped storage power station. It can alleviate the difficulty of peak shaving caused by the difference between peak load and valley load, which is of great practical and strategic significance for improving the efficiency of China's power grid. Under the premise of 100% utilization of wind power and solar power, the electrolytic aluminum system can overload the grid power of the utility grid, which is more than 30% more than conventional pumped storage power stations. For example, a new type of electrolytic aluminum project has a peaking capacity of 1 million. At KW, it is equivalent to saving 8 billion yuan in investment, and also saving more than 30% of electricity. It also saves construction land and protects the environment.

3) The power control method of the non-in-grid multi-energy collaboratively powered electrolytic aluminum system of the present invention has a good business prospect. The power control method of the non-integrated multi-energy coordinated power supply electrolytic aluminum system of the invention makes the electrolytic aluminum industry change from a high energy-consuming industry to a green and grid-friendly sustainable emerging industry, which has good economic, social and environmental benefits. The comprehensive economic benefits are much higher than the conventional electrolytic aluminum projects. The invention can quickly promote the structure and spatial layout of high-energy industrial buildings in China to reduce carbon dioxide emissions per ton of wind power aluminum by 12 tons. For example, 80% of aluminum production in China is produced by this method, with an annual standard coal of 44.88 million tons and carbon dioxide emission reduction of 126 million tons. .

detailed description

Example

The power control method for the electrolytic aluminum system of the non-grid-connected multi-energy cooperative power supply of the embodiment, wherein the electrolytic aluminum system comprises an electrolytic aluminum device, a wind power generation device and a solar power generation device, and the wind power generation device and the solar power generation device are in a non-grid-connected form. The electrolytic aluminum device is supplied with power, and the waste heat emitted from the electrolytic aluminum device is recovered and then generated and supplied to the aluminum electrolytic cell.

In this embodiment, when the utility grid is in a peak period, the amount of electricity supplied by the utility grid to the aluminum electrolysis cell is the minimum amount of electricity required for the heat preservation operation, and the amount of electricity generated by the wind power generation device and the solar concentrating power generation device is taken as Supplementary; when the utility grid is in the valley period, the power supply restriction of the utility grid to the electrolytic aluminum device is cancelled. In this example, the minimum amount of electricity required for the operation of the electrolytic aluminum device for heat preservation is the amount of power required to maintain the aluminum electrolytic cell of the electrolytic aluminum device only when the electrolytic aluminum liquid is kept at 860-980 ° C when the residual heat is not recovered. In this way, the peak-to-valley electricity price difference of the utility grid can be fully utilized to improve the economic efficiency of the enterprise, and deep peak shaving is performed for the utility grid.

The power output of solar power generation equipment and wind power generation equipment fluctuates greatly, the degree of uncertainty is very high, and it is difficult to adjust. It often requires high power generation reserve capacity and spare capacity of transmission network, which has become a serious obstacle to the scale of wind power generation and solar power generation. . The solar power generation device and the wind power generation device of the present embodiment creatively use the non-grid-connected way to supply power to the electrolytic aluminum system, and can adapt to the fluctuation characteristics of large-scale wind power and solar power generation, thereby avoiding the safety of the wind power and solar power generation grid-connected to the power grid. Stability, operating height and other aspects to ensure the safety and economic operation of the power system.

The embodiment can also be improved as follows: The solar power generation device adopts a solar concentrating power generation device, and the solar concentrating power generation device is provided with a tubular receiver, and the waste heat emitted by the electrolytic aluminum device is transmitted to the tubular receiving of the solar power generation device through the pipeline through the heat conduction medium. Therefore, the solar power generation device can be utilized for waste heat power generation. In the embodiment, the heat transfer medium may be a molten salt or a heat transfer oil.

The present invention is not limited to the specific technical solutions described in the above embodiments, and any technical solution formed by equivalent replacement is the protection scope required by the present invention.

Claims

claims

1. A power control method for an electrolytic aluminum system with non-grid-connected multi-energy collaborative power supply. The electrolytic aluminum system includes an electrolytic aluminum device, a wind power generation device and a solar power generation device. The electrolytic aluminum device is equipped with an aluminum electrolytic cell; It is characterized in that: the wind power generation device and the solar power generation device provide power to the electrolytic aluminum device in a non-grid-connected manner, and the waste heat emitted by the electrolytic aluminum device is recovered to generate electricity and supply it to the aluminum electrolytic tank; when the public power grid is at its peak. During the period, the public power grid supplies power to the electrolytic aluminum device according to the minimum amount of electricity required by the electrolytic aluminum device for heat preservation operation, and the electricity generated by the wind power generation device and the solar concentrator power generation device serves as a supplement; when the public power grid is in the valley period , then the public power grid cancels the restriction on supplying power to the electrolytic aluminum device according to the minimum amount of electricity required for the heat preservation operation of the electrolytic aluminum device.

2. The power control method of an electrolytic aluminum system with non-grid-connected multi-energy collaborative power supply according to claim 1, characterized in that: the solar power generation device is a solar concentrator power generation device, and the solar concentrator power generation device is provided with Tubular receiver, the waste heat emitted by the electrolytic aluminum device is transmitted to the tubular receiver of the solar power generation device through a pipeline using a heat-conducting medium, so that the solar power generation device can be used to generate waste heat power.

3. The power control method of the non-grid-connected multi-energy collaborative power supply electrolytic aluminum system according to claim 1, characterized in that: the minimum amount of electricity required for the heat preservation operation of the electrolytic aluminum device is only for the electrolytic aluminum device. The amount of power required to maintain the electrolytic aluminum liquid at 860-980°C when the aluminum electrolytic cell is insulated and no longer recovers waste heat.

4. The power control method of the non-grid-connected multi-energy collaborative power supply electrolytic aluminum system according to any one of claims 1 to 3, characterized in that: the heat transfer medium is molten salt or heat transfer oil.