Burn the coal -fired power generation of 1.6 billion tons of coal every year, but can it become a promoter of low -carbon power in the future?| Lu Qinggang

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Our research for decades,

It is mainly to follow the major needs of the country.

What kind of coal power needs,

What technology do we develop and develop.

Lv Qinggang · Researcher at the Institute of Engineering Thermal Physics of the Chinese Academy of Sciences

Gezhi Tao Tao 83 | June 25, 2022 Beijing

Hello everyone, I am Lu Qinggang from the Institute of Engineering Thermal Physics of the Chinese Academy of Sciences. My report theme is "Promotion of Coal: Promotion of Low -Carbon Power".

How can coal and low -carbon connect together?

The following photo is the Poto Power Plant in Hohhot, Inner Mongolia. It is a modern coal -fired power plant with an installed capacity of 6.72 million kilowatts. It is mainly powered by Beijing. In every three lamps in Beijing, one is lit by the Toto Power Plant.

There are more than 1,000 modern coal -fired power plants like this. They realize the ultra -low emissions of conventional pollutants such as nitrogen oxides, sulfur dioxide and dust, reaching the world's advanced level.

Our national coal -fired power generation accounts for 60%of the power supply of electricity, which is the main force of power generation. It burns 1.6 billion tons of coal each year. The main component of coal is carbon, and carbon dioxide discharged by combustion, so coal power is a large household of carbon dioxide emissions.

Carbon emissions in various fields in my country in 2020

Our country emits 10 billion tons of carbon dioxide each year, of which 4.2 billion tons are used. Since it will emit so many carbon dioxide, can we not use coal? Can you only use renewable energy? We use the two examples below back and forth

Left: Vehicles in the severe cold weather in extreme Blizzard

Right: US power outage map on February 15, 2021

In Texas, the renewable energy in the United States accounted for 24%. In the extreme weather in February last year (2021), renewable energy stopped. At that time, the shortage of electricity was very obvious, the price increased by 200 times, and the lives of four or five million families were affected.

The situation of our country was a bit complicated. Last year, the gap in various local power reached 10%-20%, so it was common to pull the gate at that time. Especially in Liaoning in the northeast, under extreme conditions, wind power generation has dropped sharply, and there are almost almost no electricity. The power gap continues to expand. In order to prevent the collapse of the power grid, we have no choice but to limit power, which has a great impact on industrial production and life. Because there is no choice, it means that who may use more uses, it is directly pulled off. Especially for the steel industry, hospitals, and some special departments, it is very troublesome.

Therefore, our demand for stable power output is very urgent. The volatility and interval of renewable energy are very serious. It is not only manifested in the daytime, no electricity at night, but also sometimes more electricity, sometimes less electricity, and even a few days without electricity.

With the development of new electrification, our requirements for stable power output are more harsh. So there is a contradiction between unstable renewable energy and demanding stable power output. Therefore, we need a huge power supply to achieve a balance between unstable renewable energy and stable power output. In other words, in the process of using renewable energy, this huge power supply must be prepared at all times. When there is no renewable energy, it must be replenished immediately. This is the concept of peak adjustment.

So how to achieve peak transfer? Some people say that energy storage can solve this problem. But don't forget that my country ’s coal and electricity burns 1.6 billion tons a year, and the technology of energy storage can not achieve this large -scale long -term peak adjustment.

From the two examples just now, we can see that the gap in the power is not a moment, but for a few days. There are tens of millions of watts of the gap, while the advanced energy storage single -machine capacity is only 100,000 kilowatts. 10,000 kilowatts and short -term. At the cumulative calculation of time and power standards, they actually have 3 to 4 magnitude of magnitude. So how does advanced countries solve this problem? The proportion of renewable energy in Europe and the United States is relatively high, reaching 20%or even 50%. Europe uses natural gas as a raw material for gas turbines to generate electricity to solve the problem of peak adjustment. The ingredients of shale gas and shale gas are comparable to natural gas, mainly methane.

The gas turbine with natural gas as fuel has the benefits of efficient and cleaning. For example, under the same power conditions, the amount of carbon dioxide emitted with natural gas power generation is 55%of coal power generation. We can also call natural gas as a relatively low -carbon energy source. So, can our country also use natural gas?

In addition to abundant reserves, the price of coal is 1/6 of natural gas and 1/9 of petroleum

However, the status quo of our country is coal rich, oil deficiency, and less gas. Natural gas accounts for only 3%of fossil energy reserves. At present, nearly 50%of natural gas depends on imports, and it is mainly used to ensure people's livelihood, so it is unlikely to use natural gas to adjust peaks. So what do we do? At present, we are mainly coal -fired power generation, and coal power is the only choice, because coal is the cheapest and the most reserves.

Coal combustion technology, synchronize with national development

Completed: 30%///////////

Our research in the past few decades is mainly to follow the major needs of the country, what kind of coal power needs, and what kind of technology we have developed.

Left: In 1982, Beijing Zhongguancun 2.8MW circulating fluidized bed coal -fired boiler (my country's first CFB industrial device)

Middle: 1989 Mingshui 35T/H circulating fluidized bed coal -fired boiler (my country's first CFB power generation boiler)

Right: In 1992, the leaders of relevant national ministries and commissions witnessed the scientific and technological achievement appraisal of 75T/H circulating fluidized bed boiler

In the 1980s, during the period of reform and opening up, the economic development was rapid. At that time, the quality of coal in my country was uneven. It was necessary to achieve efficient combustion of coal and solve the problem of fuel adaptability. Therefore, we have developed a technology called circulating fluidized bed boiler to achieve the clean and efficient combustion of coal through it. In 1982, we established the first industrial device in Zhongguancun, Beijing to complete the research and development and iteration of technology; in 1989, the application of the power generation industry was realized in Shandong; by 1992, the leaders of various national ministries and commissions witnessed us 75 tons of 75 tons The identification of cyclic fluidization bed boilers has since moved to research and development of large -scale and batch applications. This product is also applied to the north and south of the motherland, and finally achieved industrial applications of more than 3,000 devices.

Left: 2002 Gansu Kiln Street 130T/h medium temperature medium pressure circulating fluidized bed coal -fired boiler

Middle: 2007 Inner Mongolia Yili 200MW ultra -high pressure reinforcement circulating fluidized bed coal -fired boiler

Right: 2012 Sichuan White Horse 600MW supercritical circulating fluidized bed coal -fired boiler

After 2000, our economy has developed rapidly and the demand for electricity has gradually improved. At this time, we face the problem of how we can improve the efficiency of power generation and power generation capabilities. Therefore, we have studied large -capacity and high parameters boilers, from low parameters to ultra -high voltage to supercritical parameters, and we have all carried out research and development and application, so that the coal consumption of power supply has been reduced from 392 grams in 2000 to 333 grams per 2010 grams per 2010 gram Du electricity has achieved significant reduction.

In 2010, haze became the focus of society. How to solve the problem of haze became the focus of our work. By controlling the fuel combustion process, we have achieved ultra -low emissions of nitrogen oxides and directly meet the national standards. Until now, more than 90%of our country's power plants have achieved ultra -low emissions. It can also be said that the pollution of coal -fired power generation is no longer the main source of air pollution.

In the context of double carbon, my country has put forward new challenges to coal power, which is the issue of peak adjustment. Our past power generation devices were designed in accordance with the requirements of high burden, and the device used for peak adjustment now requires that it runs under low load. At low load, the current power generation device is not burned well and the lift is also very slow. This is a special feature of solid fuel. So we are thinking, how can we burn coal better?

How to make coal burn like a gas?

Completed: 60%///////////

We think of the burning of gas. Like the gas stove used by every household, the gas stove is very convenient to adjust.

Left: Gas burning, small flames can also be burned stably, cleaning and non -pollution

Right: The solid burning, the temperature is easy to go out when the temperature is low, and the combustion is not sufficiently polluted

A long time ago, many people used honeycomb coal to warm and cook. It is difficult to ignite honeycomb and coal, which requires attractives. After the honeycomb coal is ignited, it is difficult for you to adjust the size of the fire. If you want to be large, you want to go to the blow, and when you want to be small, we often need to put the pot to solve this problem.

Therefore, it can be seen that solid combustion is more difficult than burning, but now we have no natural gas. How can we use coal to solve this problem? We put forward an idea, can coal be as good as gases? We have thought about many ways. One of the methods is to accompany the burning, mix a little breath, a little oil, can it work? The effect is very good, but the oil and gas are shortage, and our coal has 1.6 billion tons, which is too large. Can we burn with catalytic? The effect of combustion is very good, but the catalyst it uses is expensive. We naturally think that we can turn coal into gas, but this cost is also very high. What should I do in this large -scale and low -cost constraints? By thinking and research, we put forward a hypothesis, can we develop a type of gas to achieve the role of flexible peak adjustment?

By heating, coal becomes hot -modified fuel

We thought of a method through mechanism analysis and various experiments that this method was thermal reform. In other words, heated a part of the coal and use its own heat to achieve the modification of the entire coal, so that it gasified a part of the solid.

The higher the ingredients, the more expensive the cost. We thought, how to reduce the gasification share. When the cost drops, the scale can also be expanded. However, when the gasification of gasification is too low, the effect of solid burning is not good. Therefore, we have to find a balance between the proportion and cost of gasification.

Finally, through repeated experiments and research, we reached a basic indicator, that is, when the gas accounts for 60%, the solid accounts for 40%. Its scale, cost, and economy meet the combustion of our large -scale coal.

Left: Before the modification

Right: After modification

The gas is very good, but what about the solid part? It can be seen from the above figure that before the modification, the surface of the coal particles is smooth and dense; after the modification, the coal particles become honeycomb, pores, loose, and more oxygen easily enter. Its burning rate can reach 20 times that of conventional coal, achieving fast and fully combustion.

Engineering application that realizes fuel modification

Completed: 80%///////////

In the case of understanding these mechanisms, we want to make technology practical. Generally speaking, it is very difficult from mechanism to small tests to industrial use. Many technologies are mechanically good, but it is difficult in industrial applications.

Break through many difficulties, complete the test verification, form a preheating combustion technology and

equipment

After nearly ten years of hard work, our team has done hundreds of large -scale experiments, accumulated for more than 3,000 hours of experimental time, and only the different structures with different modifiers, we have used more than 50 test components. These parts have now become "corpses", but also laid the foundation for our success.

Carry out the working environment of the study and industrial test research

During the development process of the device, improvement, improvement, repair and system processing are commonplace for us. Our team adheres to the mission and responsibility of scientific researchers, and perseveres the test. It can be said that there is no good body to do scientific research.

Preheat Burning Boiler in Shandong Mengyin Industrial Park

Then with this foundation, there is an industrial park in Mengyin, Shandong, the old revolutionary district. Therefore, the steam boiler to provide steam boilers to the park requires high load production during the day, and in the evening, it needs to be used to prepare ultra -low load. They found a lot of people, and many conventional technologies could not meet this requirement. At this time he found us, and we used thermal modified technology to form a boiler of preheated combustion, and finally met this requirement. The minimum load of the boiler can reach 15%, it can be burned steadily, and the emissions of nitrogen oxides directly reach the standard of ultra -low emissions.

Make peak adjustment with coal burning like gas

The engineering application of fuel modification also lays the foundation for the realization of the double carbon target. In 2020, the installed capacity of our country's landscape power generation accounted for 24%. Online. In 2060, we will have a lot of renewable energy access, especially wind power and solar energy. How can we achieve its stable supply? We are to solve the problem of coal -to -electricity peaks.

From the above example, we can see that coal burning can really be like a burning gas and can achieve peak adjustment. We believe that the preheating combustion technology can enable the power grid to open up, all accept the access to renewable energy, and ensure the stable output of power, greatly reduce the emission reduction of carbon dioxide, and lay the foundation and guarantee for the dual carbon target.

thank you all!

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