Low-rank coal purification power generation system

Abstract

The invention provides a low-rank coal purification power generation system. The low-rank coal purification power generation system comprises a boiler, a steam turbine used for power generation and a power plant coagulator enabling steam to be coagulated into water. A steam exhaust port of the boiler is connected with a gas inlet of the steam turbine, an exhaust port of the steam turbine is connected with a gas inlet of the power plant coagulator, a liquid outlet of the power plant coagulator is connected with a liquid inlet of the boiler, a fuel inlet of the boiler is provided with a drying device used for drying low-rank coal and a directly-heated-type thermal decomposition furnace which can conduct thermal decomposition on the dried low-rank coal to generate semi-coke is installed between the boiler and the drying device. The semi-coke generated after the low-rank coal in the low-rank coal purification power generation system is purified is used for burning in the boiler, therefore, the boiler burning efficiency is directly increased and the investment is lowered.

Description

technical field [0001] The invention relates to a power generation system using coal, in particular to a low-rank coal purification power generation system. Background technique [0002] With the acceleration of the process of global economic integration, oil resources are becoming increasingly scarce, and energy and environmental issues have become bottlenecks restricting the economic development of many countries. Adopting advanced and reliable technologies and developing coal-based energy industries have become an important part of the world's energy industry development strategy. direction. The "Twelfth Five-Year" Special Plan for the Development of Clean Coal Technology and Technology pointed out that the focus should be on improving coal quality and pollutant removal; The target is that by 2015, the national energy consumption per 10,000 yuan of GDP will drop to 0.869 tons of standard coal (calculated at the price in 2005), which is 16% lower than the 1.034 tons of st...

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Problems solved by technology

[0003] China is short of oil and gas, and coal resources account for about 69% of my country's primary energy consumption. It is a country with relatively rich coal resources, in which low-rank coal, long-flame coal, high-volatility, weakly caking sub-bituminous coal and other low-rank coal reserves account for 58%, but low-rank coal, especially low-rank coal, due to its high water content, high volatile matter, low calorific value, well-developed pores, poor thermal stability, and easy spontaneous combustion, direct combustion has low efficiency and large energy loss. During the process, the nitrogen oxides adsorbed in the voids, the hydrocarbons in the volatile matter of insufficient combustion, and the fine dust are discharged into the atmosphere along with the flue gas, which seriously pollutes the environment and limits the use radius and utilization efficiency of low-rank coal. In the long run, China's economic development will still rely on thermal power generation.

[0004] Low-rank coal production areas are mostly areas with lack of water resources, fragile ecological environment, and small economic aggregate. They are converted on-site by means of power generation and large-scale coal chemical industry development, and are easily constrained by two factors: water resource bottlenecks and environmental capacity bottlenecks. ; When low-rank coal is directly used for combustion in power plant boilers, there are many problems such as low thermal efficiency, large selection of pulverizing system, high plant power consumption, high equipment investment, low net efficiency of power plants, and large discharge volume of flue gas tail; After simple drying, due to the high volatile content in dry coal, when it is directly used for combustion in power plant boilers, there is an explosion problem in the pulverizing system, and at the same time, the temperature of the boiler furnace is not high, so that the coal combustion is insufficient; low-rank coal contains There is a large amount of coal tar, and China is short of oil and gas, so when it is directly used for combustion in power plant boilers, a large amount of coal tar is relatively wasted; low-rank coal, especially low-rank coal, due to its high water content, high volatile matter, low calorific value, Pores are developed, thermal stability is poor, and it is easy to spontaneously ignite. Direct combustion has low efficiency and large energy consumption. The flue gas is discharged into the atmosphere, which seriously pollutes the environment and limits the use and utilization efficiency of low-rank coal

[0005] At the same time, the waste heat in the production process of the power plant and the low-temperature pyrolysis process of low-rank coal cannot be efficiently utilized. Most of the waste heat is discharged and treated, resulting in a large waste of energy; Problems such as insufficient utilization of waste heat from coal purification

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