CN203203362U - A system for drying lignite by using waste heat from power stations coupled with solar energy - Google Patents

Abstract

A system for drying lignite by utilizing waste heat of an electric power station and thermal coupling solar energy comprises a coal-fired power generation device and a lignite heating and drying device, and is characterized in that: the lignite heating and drying device comprises a lignite heater, a lignite dryer, a solar heat collecting plate and an air-water heat exchanger, wherein the lignite heater is connected with the lignite dryer, a circulating water outlet pipeline is divided into a lignite heating branch and an air heating branch, the lignite heating branch is communicated with a cooling tower after passing through the lignite heater, the air heating branch is communicated with the cooling tower after passing through the air-water heat exchanger, a gas inlet of the air-water heat exchanger is communicated with an air blower, a gas outlet of the air-water heat exchanger is communicated with a hot air pipeline, and the hot air pipeline is connected with the lignite dryer after being heated by the solar heat collecting plate. The utility model discloses the heat source of dry brown coal is derived from the circulating water and the solar energy of power plant, has fine drying potential, can satisfy the extensive brown coal drying task of power plant, reduces the operation danger and the unreliability that the high moisture brown coal of burning brought for generating set.

Description

A system for drying lignite by using waste heat from power stations coupled with solar energy

technical field

The utility model relates to a coal-fired power generation system, in particular to a system for drying lignite by using the residual heat of a power station coupled with solar energy. the

Background technique

Lignite contains a lot of moisture, which not only increases its transportation cost, but also affects the operation of boilers, reduces the efficiency of power plants, and increases the emission of greenhouse gases and various pollutants. Therefore, it is necessary to dry lignite before burning lignite in power plants, which is conducive to improving the efficiency of boiler units and reducing the emission of carbon dioxide, nitrogen oxides, sulfur oxides and other pollutants, and has important engineering practical value. Lignite drying is usually completed by heating in special drying equipment, which consumes a certain amount of heat. the

At present, energy saving and emission reduction of large thermal power generating units is one of the important national policies. The temperature of circulating water in power plants is low, and the quality of the energy contained in them is poor. There have always been few ways to recover residual heat. Therefore, the development of waste heat recovery and utilization technology for circulating water in power plants has created a new way for power plants to save energy and reduce emissions, which is very important for improving the thermal economy of power plants , It is of great significance to increase the economic benefits of the power station. the

As an inexhaustible energy source, solar energy has the advantages of cleanness, environmental protection, and widespread and long-lasting existence. It is one of the important choices for human beings to deal with energy shortages, climate change, and energy conservation and emission reduction. When electricity, coal, oil and other non-renewable energy resources are frequently running out, and energy issues have increasingly become a bottleneck restricting the development of the international society and economy, more and more professionals have begun to develop solar energy resources and seek new impetus for economic development. the

To sum up, if the waste heat utilization of circulating water in power plants can be organically combined with solar heating to realize the drying of lignite, the energy consumed for lignite drying can be greatly saved, and the purpose of energy saving and emission reduction can be achieved at the same time, and it is conducive to the promotion of low-quality lignite. coal use. the

Utility model content

The problem to be solved by the utility model is to provide a system for drying lignite by adopting an energy-saving mode to dry lignite and improving the thermal economical utilization of the power station by coupling solar energy to the waste heat of the power station. the

The said problem of the utility model is solved by the following technical solutions:

A system for drying lignite using waste heat from a power station coupled with solar energy, which includes a coal-fired power generation device and a lignite heating and drying device. The coal-fired power generation device includes a boiler, a steam turbine, a condenser, and a cooling tower. The pipeline and the circulating water outlet pipeline are connected, and its special features are: the lignite heating and drying device includes a lignite heater, a lignite dryer, a solar heat collector, an air-water heat exchanger, and the lignite heater is connected to the lignite dryer , the circulating water outlet pipeline is divided into a lignite heating branch and an air heating branch, the lignite heating branch is connected to the cooling tower after passing through the lignite heater, and the air heating branch is connected to the cooling tower after passing through the air-water heat exchanger, and the air-water exchange The gas inlet of the heater is connected to the blower, the gas outlet of the air-water heat exchanger is connected to the hot air pipeline, and the hot air pipeline is connected to the lignite dryer after being heated by the solar heat collecting plate.

In the above-mentioned system for drying lignite using waste heat from a power station coupled with solar energy, the lignite dryer is a fluidized bed dryer; the lignite heater is provided with a heating pipe connected to a lignite heating branch. the

In the above-mentioned system for drying lignite using waste heat from a power station coupled with solar energy, the upper part of the lignite dryer is connected to a dust collector, and the dust collector is connected to a chimney. the

In the above-mentioned system for drying lignite using waste heat from a power station coupled with solar energy, the lower part of the lignite dryer is connected to a pulverized coal box, and the pulverized coal box is connected to a boiler. the

In the above-mentioned system for drying lignite using waste heat from a power station coupled with solar energy, the cooling tower is communicated with the circulating water inlet pipeline. the

The utility model aims at the problem of effectively utilizing the waste heat of circulating water in a power plant combined with solar energy to dry lignite, and designs a system for drying lignite by using power plant waste heat coupled with solar energy. The system divides the circulating water out of the condenser into two paths: one path enters the pipeline in the lignite heater as the heat source medium for heating the lignite; the other path is connected to the heat exchanger to initially heat the air from the blower, and then circulate The air heated by water enters the solar collector plate to be heated again, and then enters the lignite dryer to dry the lignite heated by the circulating water; the circulating water after waste heat utilization enters the cooling tower of the power plant. The advantages of the system are as follows: 1. The waste heat of the circulating water of the condenser belongs to the cold end of the working fluid cycle of the power plant. The waste heat of the circulating water is used to heat lignite and air, and the temperature of the cold end of the steam-water cycle of the power plant is reduced while the waste heat is utilized, improving 2. The use of solar collectors makes the air temperature directly involved in the drying of lignite reach a higher level, and the drying degree of lignite is also greater, which improves the work output of the system and operating efficiency. 3. The overall thermal parameters of the system are below 100°C, which is far lower than the temperature of the main drying heat source of conventional lignite drying equipment. Therefore, lignite will not cause spontaneous combustion or deflagration during the entire drying process, so the system is safe and reliable. 4. The system layout is simple, the process is short, the heat source of the system mainly comes from the circulating water and solar energy of the power plant, and the power plant has a large amount of circulating water and has good drying potential, so the single machine processing capacity of the system Large, it can meet the large-scale lignite drying task of the power plant. The utility model can greatly improve the combustion efficiency of the boiler, and at the same time reduce the operation risk and unreliability brought by burning high-moisture lignite to the generating set. Due to the use of low-cost heat sources such as power plant circulating water waste heat and solar energy to dry lignite, the economic cost will not increase significantly, and it is operable in practical engineering applications. the

Description of drawings

Fig. 1 is the schematic diagram of the utility model system. the

The meaning list of the labels in the accompanying drawings is: 1. Chimney; 2. Dust collector; 3. Lignite heater; 4. Lignite dryer; 5. Pulverized coal box; 6. Boiler; 9. Steam turbine; 10. Lignite heating branch; 11. Air heating branch; 12. Circulating water inlet pipeline; 13. Solar heat collector; 14. Air-water heat exchanger; 15. Cooling tower; 16. Blower ; 17. Hot air pipeline. the

Detailed ways

Referring to Fig. 1, the utility model comprises a coal-fired power generation device and a lignite heating and drying device. , The circulating water outlet pipeline is connected. The exhausted steam discharged from the steam turbine 9 is condensed into water in the condenser 8, and the heat is released to the circulating water to raise the temperature of the circulating water. After the condensed water comes out of the condenser 8, it passes through the feed water pump 7 and returns to the boiler 6 to absorb heat and evaporate. Complete the steam water process of the power plant. the

Still referring to FIG. 1 , the lignite heating and drying device includes a lignite heater 3 , a lignite dryer 4 , a solar collector plate 13 , and an air-water heat exchanger 14 . The lignite dryer is connected with the lignite heater, and the lignite heated by the lignite heater enters the lignite dryer for drying. The circulating water outlet pipeline is divided into a lignite heating branch 10 and an air heating branch 11 . Wherein, the lignite heating branch 10 communicates with the heating pipeline provided in the lignite heater 3, and the lignite heating branch 10 enters the cooling tower 15 after releasing heat in the lignite heater; Enter cooling tower 15 after heating. The gas inlet of the air-water heat exchanger 14 is connected to the blower 16, and the gas outlet of the air-water heat exchanger is connected to the hot air pipeline 17, and the hot air pipeline is connected to the lignite dryer 4 after being heated by the solar collector plate 13. The cooling tower 15 communicates with the circulating water inlet line 12 . the

Still referring to Fig. 1, the working process of the lignite heating and drying device of this system is as follows: the circulating water heated up by the condenser 8 is divided into two paths: one path enters the air-water heat exchanger 14, and is heated in the air-water heat exchanger. The air of the blower 16 heats up the air; the other way enters the lignite heater 3 as the main heat source medium of the lignite heater. The circulating water from the lignite heater 3 and the circulating water from the air-water heat exchanger 14 enter the cooling tower 15 of the power plant, which reduces the temperature of the cold end of the steam-water cycle of the power plant while utilizing the waste heat of the circulating water. The air heated by the circulating water enters the solar collector plate 13 and is heated again to about 85°C, and then enters the fluidized bed of the lignite dryer 4, where the lignite heated by the circulating water is dried and used as the lignite pulverized coal. As well as the medium that takes away the moisture in the lignite, the gas and moisture in the lignite dryer are dedusted by the dust removal 2, and are discharged into the atmosphere by the chimney 1. The broken lignite raw coal first falls into the lignite heater 3, is heated by circulating water, and then falls into the lignite dryer 4 to be dried by hot air. The powder box 5 is sent into the boiler for combustion. the

Claims (5)

1. A system that utilizes waste heat from a power station coupled with solar energy to dry lignite, it includes a coal-fired power generation device and a lignite heating and drying device, and the coal-fired power generation device includes a boiler (6), a steam turbine (9), a condenser (8) and The cooling tower (15), the condenser is connected with the circulating water inlet pipeline and the circulating water outlet pipeline respectively, and it is characterized in that: the lignite heating and drying device includes a lignite heater (3), a lignite dryer (4), a solar energy Heat collecting plate (13), air-water heat exchanger (14), lignite heater connected to lignite dryer, circulating water outlet pipeline divided into lignite heating branch (10) and air heating branch (11), lignite heating branch The path passes through the lignite heater (3) and then connects to the cooling tower (15), the air heating branch passes through the air-water heat exchanger (14) and then connects to the cooling tower, and the gas inlet of the air-water heat exchanger (14) connects to the blower ( 16), the gas outlet of the air-water heat exchanger is connected to the hot air pipeline (17), and the hot air pipeline is connected to the lignite dryer (4) after being heated by the solar collector plate (13). 2. The system for drying lignite using waste heat from a power station coupled with solar energy according to claim 1, characterized in that: the lignite dryer (4) is a fluidized bed dryer; the lignite heater (3) is equipped with The heating pipeline is connected to the lignite heating branch (10). 3. The system for drying lignite by using waste heat from a power station coupled with solar energy according to claim 2, characterized in that: the upper part of the lignite dryer (4) is connected to a dust collector (2), and the dust collector is connected to a chimney (1). 4. The system for drying lignite by using waste heat from a power station coupled with solar energy according to claim 3, characterized in that: the lower part of the lignite dryer (4) is connected to a pulverized coal box (5), and the pulverized coal box is connected to a boiler (6). 5. The system for drying lignite by using waste heat from a power station coupled with solar energy according to claim 4, characterized in that: the cooling tower (15) is in communication with the circulating water inlet pipeline (12).

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