CN222393206U

CN222393206U - Low-calorific-value coal drying system

Info

Publication number: CN222393206U
Application number: CN202421255912.9U
Authority: CN
Inventors: 汪枫; 赵雨; 刘文建; 吕婉婷; 张安龙
Original assignee: Sichuan Crun Power Equipment Co ltd
Current assignee: Sichuan Crun Power Equipment Co ltd
Priority date: 2024-06-04
Filing date: 2024-06-04
Publication date: 2025-01-24
Anticipated expiration: 2034-06-04

Abstract

The utility model relates to the technical field of coal-fired power plants and discloses a low-heat-value coal drying system which comprises a warm air device, an oven and a treatment device, wherein the warm air device, the oven and the treatment device are connected together to form a circulating structure, the warm air device is communicated with the oven through an air duct, low-heat-value coal to be dried is filled in the oven, the warm air device provides high-temperature air flow for drying the oven, the oven is also connected with the treatment device for dedusting and cooling exhaust gas of the oven, the treatment device and the warm air device are communicated through the air duct, and the treatment device is communicated with the warm air device through the air duct. The utility model has the beneficial effects of greatly saving resources, protecting environment, saving manpower, reducing drying cost, improving drying efficiency and saving labor cost.

Description

Low-calorific-value coal drying system

Technical Field

The utility model relates to the technical field of coal-fired power plants, in particular to a low-calorific-value coal drying system.

Background

Fossil fuel is a non-renewable resource, and in order to adapt to the change of energy structures, many power plants begin to mix and burn low-heat-value coal, the low-heat-value coal is coal with lower heat generated when completely burning, if the low-heat-value coal is not used, resources are wasted, the environment is polluted, measures can be taken to recycle the low-heat-value coal, but the moisture content in the low-heat-value coal is too high, the low-heat-value coal mixed at present is widely applied in the coal-fired power plants, and the transportation of the low-heat-value coal mixed in the boiler becomes difficult due to the high moisture content, easy sticking and easy caking of the low-heat-value coal mixed at present.

The low-heat-value coal is mixed and fed into a coal mill in a common mode, the low-heat-value coal is injected into the hearth from the top of the hearth by adopting a booster pump, the low-heat-value coal is blocked in a pipeline in the two modes, the moisture content of the low-heat-value coal is high, the heat value is 2000-3000 kcal/kg, the efficiency of a boiler is influenced during mixing, and the low-heat-value coal is often subjected to drying treatment.

The existing low-calorific-value coal drying mode is easy to cause energy waste, can also cause environmental pollution due to exhaust, and the exhaust is limited by the emission requirement, so that the drying cost is higher and the efficiency is lower.

Disclosure of utility model

In order to overcome the problems of energy waste and environmental pollution caused by tail gas emission in the low-calorific-value coal drying mode in the background technology, the utility model provides the low-calorific-value coal drying system, which can achieve zero tail gas emission through a warm air device, an oven and a treatment device which form a circulating structure, and the air flow for heating can be recycled, so that the low-calorific-value coal drying system has the beneficial effects of greatly saving resources, protecting the environment, saving manpower, reducing the drying cost, improving the drying efficiency and saving the labor cost.

The technical scheme of the utility model is as follows:

The utility model provides a low calorific value coal drying system, includes that the connection forms circulation structure's warm braw device, oven and processing apparatus together, warm braw device passes through the wind channel intercommunication with the oven, is equipped with the low calorific value coal of waiting to dry in the oven, and the warm braw device provides the high-temperature air current of stoving for the oven, and the oven still links to each other with the processing apparatus who removes dust and cool off its exhaust gas, and both pass through the wind channel intercommunication, processing apparatus communicates with each other through the wind channel with the warm braw device.

Compared with the prior art, the beneficial effect of this technical scheme lies in:

(1) The system adopts a convection heat exchange mode to dry low-heat-value coal, heat is transferred through the convection heat exchange, the high-temperature air flow heated in the warm air device is sent into the oven, the high-temperature air flow and the low-heat-value coal are subjected to the convection heat exchange, the heat value of the low-heat-value coal in the oven is improved, the low-heat-value coal is dried, and the problem that the low-heat-value coal is blocked in a pipeline due to bonding is solved;

(2) The whole system adopts the circulating utilization air flow, fully utilizes energy sources, simultaneously does not discharge tail gas, avoids environmental pollution caused by the discharged tail gas, reduces drying cost and improves drying efficiency;

(3) The whole process can realize automatic operation, and labor cost is saved.

Preferably, the warm air device comprises a warm air device, a heating channel of the warm air device is a closed cavity, a plurality of uniformly arranged heating pipelines are arranged in the heating channel, high-temperature steam is introduced into the heating pipelines, and air flow passing through the heating channel is heated.

Further preferably, the air inlet of the heating pipeline is communicated with a low-pressure steam pipeline of the steam turbine, and a heating steam source is provided for the warm air device.

Further preferably, an outlet of the heating pipeline is connected with a water tank, and the water tank conveys the condensed water to the deaerator for recycling through a water pump.

Preferably, the processing device comprises a dust remover, and an air inlet of the dust remover is communicated with an air outlet of the oven through an air channel.

Further preferably, the processing device further comprises a cooling device, the cooling device comprises a first-stage heat exchanger and a second-stage heat exchanger which are of closed structures, the air outlet of the dust remover is communicated with the air inlet of the first-stage heat exchanger through an air duct, cooling water is communicated in the heat exchange pipeline of the first-stage heat exchanger and is communicated with the heat exchange pipeline of the second-stage heat exchanger through a circulating water pipeline, the air outlet of the first-stage heat exchanger is communicated with the air inlet of the second-stage heat exchanger through an air duct, and the air outlet of the second-stage heat exchanger is communicated with the air inlet of the warm air device through an air duct.

Further preferably, a circulating fan is arranged on an air duct connecting the first-stage heat exchanger and the second-stage heat exchanger.

Further preferably, the water inlet of the heat exchange pipeline of the first-stage heat exchanger is communicated with the water outlet of the condensing tower through a circulating water pipeline, the condensing tower provides cooling water for the condensing tower, and the water outlet of the heat exchange pipeline of the second-stage heat exchanger is communicated with the water inlet of the condensing tower through a circulating water pipeline, so that the cooling water is recycled.

Further preferably, a circulating water pump is arranged on a circulating water pipeline connecting the first-stage heat exchanger and the condensing tower.

Further preferably, the air duct is made of steel plate, forming a closed air circulation system.

Drawings

The utility model will be described by way of reference to the accompanying drawings, in which:

Fig. 1 is a schematic diagram of the overall structure of the present utility model.

The air heater comprises a heating device 1, a heater 10, a heating channel 11, a heating pipeline 110, a steam turbine 12, a water tank 13, a water pump 14, a deaerator 15, an oven 2, a feeding port 21, a discharging port 22, a conveyor belt 23, a dust remover 3, a cooling device 4, a first-stage heat exchanger 41, a second-stage heat exchanger 42, a heat exchange pipeline 43, a condensing tower 44, a circulating water pipeline 45, a circulating water pump 46, an air duct 5 and a circulating fan 51.

Detailed Description

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

Embodiment 1A low calorific value coal drying system as shown in figure 1 comprises a warm air device 1, a drying oven 2 and a processing device which are connected together to form a circulating structure, wherein an air outlet of the warm air device 1 is communicated with an air inlet of the drying oven 2 through an air channel 5, low calorific value coal to be dried is filled in the drying oven 2, the warm air device 1 provides high temperature air flow for drying the drying oven 2, the air outlet of the drying oven 2 is communicated with a processing device for dedusting and cooling exhaust gas of the drying oven 2, the air outlet of the drying oven 2 is communicated with the air inlet of the processing device through the air channel 5, the air outlet of the processing device is communicated with the air inlet of the warm air device 1 through the air channel 5, a feeding opening 21 is further arranged at the top of the drying oven 2, a discharging opening 22 is arranged at the bottom of the drying oven 2, a plurality of conveying belts 23 which are arranged along the horizontal direction are fixed in the drying oven 2, the running directions of the adjacent conveying belts 23 are opposite, the low calorific value coal at the end point of each layer of the conveying belts 23 is required to fall into the starting points of the adjacent conveying belts below the starting points of the conveying belts, namely the starting points of the conveying belts 23 which are positioned above the adjacent to the starting points of the conveying belts 23, extend in the running directions of the conveying belts 23 above the adjacent conveying belts 23. All air channels 5 in the system are made of steel plates, so that a closed air flow circulation system is formed.

The low-heat-value coal enters the conveyor belt 23 from the feeding port 21 and reaches the discharging port 22 along the conveying direction of the conveyor belt, the high-temperature air flow generated in the warm air device 1 enters the oven 2 from the air inlet of the oven 2 through the air duct 5 and flows along each layer of conveyor belt 23 to be fully contacted with the low-heat-value coal, the high-temperature air flow carries out convection heat exchange with the low-heat-value coal, so that the water in the low-heat-value coal on the conveyor belt 23 is evaporated and carried by the flowing high-temperature air flow to enter the treatment device from the air outlet of the oven 2, the air flow which is fully contacted with the low-heat-value coal to carry out convection heat exchange contains more coal dust and water vapor, the treatment device can remove dust and dry the coal dust and the water vapor, the air flow after dust removal and drying enters the warm air device 1 through the air duct 5 and is heated again to form a circulating drying system.

The system dries low-heat-value coal in a convection heat exchange mode, transfers heat through convection heat exchange, conveys high-temperature air flow heated in the warm air device 1 into the oven 2, carries out convection heat exchange on the high-temperature air flow and the low-heat-value coal, improves the heat value of the low-heat-value coal in the oven 2, dries the low-heat-value coal, solves the problem that the low-heat-value coal is blocked in a pipeline due to bonding, adopts circulating air flow, fully utilizes energy, simultaneously does not discharge tail gas, avoids environmental pollution caused by the discharged tail gas, reduces drying cost, improves drying efficiency, and can realize automatic operation in the whole process and save labor cost.

Embodiment 2A preferred design is carried out on the basis of embodiment 1, the warm air device 1 comprises a warm air device 10, a heating channel 11 of the warm air device 10 is a closed cavity, a plurality of heating pipelines 110 are uniformly paved in the heating channel 11, high-temperature steam is introduced into the heating pipeline 110, heat in the high-temperature steam is transferred to air flow in the heating channel 11 in a convection heat exchange mode, and the air flow entering the warm air device 10 is fully contacted with the surface of the heating pipeline 110 to generate relative displacement, so that high-temperature air flow is formed.

Further, the air inlet of the heating pipe 110 is communicated with the air outlet of the low-pressure steam pipe of the steam turbine 12, the steam turbine 12 provides a heating steam source for the warm air device 1, the temperature of the low-pressure steam is more than 200 ℃, the outlet of the heating pipe 110 is connected with the water tank 13, the low-pressure steam after the convection heat exchange in the heating pipe 110 is condensed into water to be collected into the water tank 13, and the water tank 13 conveys the condensed water into the deaerator 15 through the water pump 14 for recycling. The low-pressure steam generated by the steam turbine 12 in the power plant is often changed into condensation water directly through the condenser, and the heat in the condensation water is released to the atmosphere and is not utilized, but in the embodiment, the heating pipeline 110 is communicated with the low-pressure steam pipeline of the steam turbine 12, the low-pressure steam heats the air flow in the heating channel 11 through the heating pipeline 110 and is used for improving the heat value of coal, so that the heat in the low-pressure steam can be fully utilized, meanwhile, the condensation effect is also achieved by the low-pressure steam, the economy of the power plant can be greatly improved, the energy is saved, the consumption is reduced, the operation safety is ensured, the utilization rate of resources is further improved, and the power plant is more energy-saving and environment-friendly.

Embodiment 3A treatment device is preferably designed on the basis of embodiment 1, and comprises a dust remover 3 and a cooling device 4, wherein the dust remover 3 is a bag-type dust remover 3, and the bag-type dust remover 3 has the advantages of large treatment air quantity per unit volume, high dust removal efficiency, low energy consumption, stability and reliability. The air inlet of the dust remover 3 is communicated with the air outlet of the oven 2 through an air duct 5, and the air flow flowing out of the oven 2 enters the dust remover 3, and the pulverized coal is filtered from the dust remover 3 and then enters the cooling device 4.

The cooling device 4 comprises a first-stage heat exchanger 41 and a second-stage heat exchanger 42 which are of closed structures, an air outlet of the dust remover 3 is communicated with an air inlet of the first-stage heat exchanger 41 through an air duct 5, cooling water is communicated in a heat exchange pipeline 43 of the first-stage heat exchanger 41, the heat exchange pipeline 43 is communicated with a heat exchange pipeline 43 of the second-stage heat exchanger 42 through a circulating water pipeline 45, an air outlet of the first-stage heat exchanger 41 is communicated with an air inlet of the second-stage heat exchanger 42 through the air duct 5, and an air outlet of the second-stage heat exchanger 42 is communicated with an air inlet of the warm air device 1 through the air duct 5. The air duct 5 connecting the first-stage heat exchanger 41 and the second-stage heat exchanger 42 is provided with a circulating fan 51, the air duct 5 in front of the circulating fan 51 is also provided with a blower, the blower blows air when the system is started, the blower is directly cut off after running, and the air flow circulates automatically.

When the air flow entering the first-stage heat exchanger 41 from the air outlet of the dust remover 3 has a certain temperature, the temperature is above 100 ℃, and when the air flow passes through the surface of the heat exchange pipeline 43 of the first-stage heat exchanger 41, cooling water is introduced into the heat exchange pipeline 43, so that hot air flow can perform convection heat exchange with the cooling water in the heat exchange pipeline 43, the cooling water is heated, the temperature of the air flow is reduced below 100 ℃, water vapor carried in the hot air flow is condensed, the condensed water is collected by a collecting box below the first-stage heat exchanger 41, the hot air flow is completed to remove water, the heat exchange pipeline 43 is communicated with the heat exchange pipeline 43 of the second-stage heat exchanger 42, the air outlet of the first-stage heat exchanger 41 is communicated with the air inlet of the second-stage heat exchanger 42 through the air duct 5, and therefore, the heated hot air in the heat exchange pipeline 43 of the first-stage heat exchanger 41 enters the heat exchange pipeline 43 of the second-stage heat exchanger 42, the cooled and dried cold air flow enters the second-stage heat exchanger 42, and contacts with the surface of the heat exchange pipeline 43 of the second-stage heat exchanger 42, the cold air flow is further heated by the convection water flow, and the air flow in the second-stage heat exchanger is heated by the air flow, and the air flow can be heated by the circulating device 1, and the air flow of the air flow can be further heated by the air flow, and the air flow can be cooled by the device, and the air flow can be further heated by the device, and the air flow can be cooled by the air flow, and the air flow can be cooled by the air, and the air flow and the device, and the device can be cooled by the air and the air.

Because the steam in the air flow is saturated, the air flow exceeding the saturation cannot carry redundant steam, and the temperature of hot air at the outlet of the dust remover 3 is higher than 100 ℃, direct discharge can cause a large amount of heat loss, and in order to reduce the heat loss, the cooling device 4 is arranged at the outlet of the dust remover 3 in the embodiment, so that the steam content in the air flow can be reduced, the heat loss is reduced, the air flow is recycled, the energy loss caused by discharge is reduced, the energy is maximally utilized, the process greatly improves the utilization rate of the heat in low-pressure steam of the steam turbine 12, and the energy is saved and the efficiency is improved.

Further, the water inlet of the heat exchange pipeline 43 of the first-stage heat exchanger 41 is communicated with the water outlet of the condensing tower 44 through a circulating water pipeline 45, the condensing tower 44 provides cooling water for the first-stage heat exchanger 41, the circulating water pipeline 45 is provided with a circulating water pump 46, and the circulating water pump 46 provides circulating power for water circulation. The water outlet of the heat exchange pipeline 43 of the second-stage heat exchanger 42 is communicated with the water inlet of the condensing tower 44 through the circulating water pipeline 45, so that hot water in the second-stage heat exchanger 42 is subjected to heat convection, heat is transferred to the air flow and then enters the condensing tower 44 for cooling, the cyclic utilization of cooling water is realized, water resources are saved, and the resource utilization rate is further improved.

The foregoing examples merely illustrate specific embodiments of the application, which are described in greater detail and are not to be construed as limiting the scope of the application. It should be noted that it is possible for a person skilled in the art to make several variants and modifications without departing from the technical idea of the application, which fall within the scope of protection of the application.

Claims

1. A low calorific value coal drying system, characterized in that it comprises a warm air device (1), an oven (2) and a processing device connected together to form a circulation structure, the warm air device (1) is connected to the oven (2) through an air duct (5), the oven (2) contains low calorific value coal to be dried, the warm air device (1) provides a high-temperature airflow for drying the oven (2), the oven (2) is also connected to a processing device for dust removal and cooling of the exhaust gas discharged from the oven (2), the two are connected through the air duct (5), and the processing device is connected to the warm air device (1) through the air duct (5).

2. A low calorific value coal drying system according to claim 1, characterized in that: the warm air device (1) comprises a heater (10), the heating channel (11) of the heater (10) is a closed cavity, and a plurality of evenly arranged heating pipes (110) are arranged inside, and high-temperature steam passes through the heating pipes (110) to heat the airflow passing through the heating channel (11).

3. A low calorific value coal drying system according to claim 2, characterized in that: the air inlet of the heating pipe (110) is connected to the low-pressure steam pipe of the turbine (12), providing a heating steam source for the warm air device (1).

4. A low calorific value coal drying system according to claim 2, characterized in that: the outlet of the heating pipe (110) is connected to a water tank (13), and the water tank (13) transports condensed water to a deaerator (15) for recycling through a water pump (14).

5. A low calorific value coal drying system according to claim 1, characterized in that: the processing device includes a dust collector (3), and the air inlet of the dust collector (3) is connected to the air outlet of the oven (2) through an air duct (5).

6. A low calorific value coal drying system according to claim 5, characterized in that: the processing device also includes a cooling device (4), the cooling device (4) includes a first-stage heat exchanger (41) and a second-stage heat exchanger (42) of a closed structure, the air outlet of the dust collector (3) is connected to the air inlet of the first-stage heat exchanger (41) through an air duct (5), cooling water passes through the heat exchange pipe (43) of the first-stage heat exchanger (41), and is connected to the heat exchange pipe (43) of the second-stage heat exchanger (42) through a circulating water pipe (45), and the air outlet of the first-stage heat exchanger (41) is connected to the air inlet of the second-stage heat exchanger (42) through the air duct (5), and the air outlet of the second-stage heat exchanger (42) is connected to the air inlet of the warm air device (1) through the air duct (5).

7. A low calorific value coal drying system according to claim 6, characterized in that a circulating fan (51) is provided on the air duct (5) connecting the first stage heat exchanger (41) and the second stage heat exchanger (42).

8. A low calorific value coal drying system according to claim 6, characterized in that: the water inlet of the heat exchange pipe (43) of the first-stage heat exchanger (41) is connected to the water outlet of the condensation tower (44) through a circulating water pipe (45), and the condensation tower (44) provides cooling water for it; the water outlet of the heat exchange pipe (43) of the second-stage heat exchanger (42) is connected to the water inlet of the condensation tower (44) through a circulating water pipe (45), thereby realizing the recycling of cooling water.

9. A low calorific value coal drying system according to claim 8, characterized in that a circulating water pump (46) is provided on the circulating water pipeline (45) connecting the first-stage heat exchanger (41) and the condensing tower (44).

10. A low calorific value coal drying system according to any one of claims 1 to 9, characterized in that the air duct (5) is made of steel plates to form a closed air circulation system.