CN203960020U - A kind of system of utilizing the dry municipal sludge of surplus heat of power plant coupled solar - Google Patents

Abstract

A system for drying urban sludge using waste heat from a power station coupled with solar energy, including: steam-water flow: a condenser, the inlet of the water channel is connected to the circulating water of the cooling tower (10), the outlet of one channel passes through the air-water heat exchanger (9), and the other channel After the sludge heater (1), both are sent back to the cooling tower (10) at last; the hot steam source of the condenser comes from the exhaust steam discharged from the steam turbine (4); the air flow: a blower (8), the air Sent to heat exchanger 9, solar heat collector plate (6) and fluidized bed dryer (2) in turn, and finally discharged into the atmosphere through dust collector 5; sludge process: the sludge pulverized by the pulverizer enters the sludge heater 1 and then fall into the fluidized bed dryer 2 and finally transported to the silo 3 by the conveyor belt. This system makes full use of the waste heat in the power plant and the solar energy in the plant area, improves the thermal economy of the power plant, and treats the sludge through drying technology to achieve stabilization, harmlessness, and reduction, laying a solid foundation for further resource utilization. foundation, has important practical significance.

Description

A system for drying municipal sludge using power station waste heat coupled with solar energy

technical field

The utility model relates to a system for drying urban sludge by utilizing waste heat of a power station coupled with solar energy.

Background technique

With the development of my country's social economy and the increase of urban population, environmental pollution is becoming more and more serious, and people's awareness of protecting and improving the living environment will inevitably lead to more and more wastewater treatment. China's sewage discharge in 2010 will reach 4.40×10 ¹⁰ m ³ /d, and it is estimated that the sewage discharge in 2020 will reach 5.36×10 ¹⁰ m ³ /d, so at least 5 million tons of sludge will be produced every year. However, practice at home and abroad shows that after the traditional concentration and dehydration process, the water content of the sludge cannot reach below 60%, and after mechanical dehydration, the water content of the sludge is about 75%. To achieve further dehydration of sludge, a more economical method is to introduce drying techniques commonly used in chemical operations, and these drying techniques will undoubtedly consume huge energy.

On the other hand, 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 energy contained in them is poor, and there have always been few ways to recover the remaining 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 power stations. At the same time, combined with the comprehensive utilization of solar energy, a new energy source, the energy quality of circulating water will be greatly improved, and the utilization efficiency of waste heat recovery will also be greatly increased. Generally, the moisture content of sludge after mechanical dehydration is about 80%, and the proportion of free moisture is relatively large, which creates conditions for low-temperature drying of sludge.

The principle of municipal sludge drying technology using the waste heat of circulating water in power plants is to heat sludge and air with circulating water at a certain temperature, and then dry the heated sludge by hot air, so as to achieve the purpose of sludge drying. After the air is preliminarily heated by the circulating water, it is then heated by the solar collector panels arranged at the outlet of the heat exchanger, and the temperature reaches 65°C. At this time, sending the air to the fluidized bed dryer to dry the sludge can achieve good results, and the sludge can be treated by drying technology to achieve stabilization, harmlessness and reduction, laying the foundation for further resource utilization , has important practical significance.

Utility model content

The technical problem to be solved by the utility model is to provide a system that utilizes power station circulating water to couple solar energy to dry urban sludge, improve the thermal economy of coal-fired power stations, and perform resource utilization for urban sludge in the next step (mixing combustion, agricultural fertilizers, soil amendments, etc.) to lay the foundation.

To solve the problems of the technologies described above, the technical solution adopted in the utility model is as follows:

A system for drying municipal sludge using circulating water coupled with solar energy in a power station is characterized in that it includes three processes of steam water, air and sludge; Circulating water and the outlet of the water channel are divided into two paths: one path passes through the air-water heat exchanger 9, and the other path passes through the sludge heater 1, both of which are finally connected to the original circulating water circulation pipeline of the power plant and sent back to the cooling tower 10; The hot steam source of the boiler comes from the exhaust steam discharged from the steam turbine 4; the air process includes: a blower 8, which sends the air through the pipeline to the heat exchanger 9 and the solar heat collector 6 to be heated and then enters the fluidized bed dryer 2 Heating the sludge, and finally passing through the dust collector 5, and discharging it into the atmosphere through the chimney after reaching the discharge standard; the sludge process includes: the sludge pulverized by the pulverizer enters the sludge heater 1 and then falls into the fluidized bed drying The container 2 is finally transported to the bin 3 by the conveyor belt.

The beneficial effects of the utility model are:

(1) The heat used in the sludge drying process is low-cost heat sources such as circulating water waste heat and solar energy, which saves a lot of drying energy, brings considerable economic benefits, and is operable in practical engineering applications.

(2) The circulating water in the system does not directly contact the sludge, and the dry air also passes through the dust collector to remove dust, so there is no secondary pollution caused by drying the sludge.

(3) The arrangement and use of solar collectors make the temperature of the air directly involved in sludge drying reach a higher level, improve the thermal parameters of the entire system, and improve the heat transfer temperature and pressure in the fluidized bed sludge heater. The drying degree of the sludge is also greater, that is, the sludge dehydration rate is also higher, which improves the work output and operating efficiency of the system.

(4) The overall thermal parameters of the system are all below 100°C, which is far lower than the temperature of the main drying heat source of conventional sludge drying equipment, and there is no high-temperature heat source for ignition, so it will not cause drying during the entire drying process. Gas in the equipment spontaneously ignites or deflagrates. Therefore, the safety and reliability of the system is much higher than that of the same type of sludge drying equipment.

(5) The system layout is simple and 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, that is, the recovered heat is also relatively large, and has a good drying potential. Therefore, the system has a large stand-alone processing capacity and can meet large-scale sludge drying tasks.

(6) The system uses circulating water as a heat source to dry sludge, and the temperature of the circulating water will definitely decrease. Therefore, for thermal power units using an air-cooling system, the energy consumption of the air-cooling system will be reduced, and the condensing water temperature of the condenser will be reduced to improve the thermal economy of the coal-fired power plant. For thermal power units that use seawater and river water as cooling water, the temperature of the final discharged cooling water will be lowered, which will effectively reduce thermal pollution to rivers and oceans.

Description of drawings

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail:

Fig. 1 is a schematic diagram of the utility model system applicable to an air-cooling unit.

The symbols in the figure are as follows: 1. Sludge heater; 2. Fluidized bed dryer; 3. Silo; 4. Steam turbine; 5. Dust collector; 6. Solar heat collector; 7. Condenser; 8 , Blower; 9, air-water heat exchanger; 10, cooling tower.

Detailed ways

The utility model provides a system for drying urban sludge by utilizing waste heat of a power station coupled with solar energy. The technical solution of the utility model will be further described below in conjunction with the accompanying drawings and specific implementation methods.

As shown in Figure 1, the sludge enters the sludge heater 1 after being pulverized, falls into the fluidized bed dryer 2 after being heated by circulating water, is dried by hot air at a higher temperature, and is finally sent to the silo by the coal conveyor belt 3. Leave it to the next resource utilization.

The exhaust steam discharged from the steam turbine 4 is condensed into water in the condenser 7, and the heat is released to the circulating water to heat up the circulating water. After the condensed water comes out of the condenser 7, the steam-water process of the power plant is completed; the circulating water in the condenser In 7, the exhaust steam of the cooling steam turbine is heated at the same time, and it is divided into two paths at the condenser outlet 7: one part enters the air-water heat exchanger 9 to heat the air from the blower 8; the other part directly enters the sludge heater through a bypass 1 as the main heat source for sludge heating. The circulating water at the outlet of the sludge heater 1 and the outlet of the air-water heat exchanger 9 gathers together, returns to the original circulating water circulation pipe of the power plant, and is sent to the cooling tower 10; the air is sent into the air-water heat exchanger 9 by the blower 8 It is heated by circulating water, and then enters the solar collector plate 6 arranged at the outlet of the heat exchanger 9 to be heated again to a higher temperature and then transported to the fluidized bed dryer 2 to dry the sludge for the second time, taking away the sludge in the sludge After the moisture is removed, the dust carried by it is recovered by the dust collector 5, and is discharged into the atmosphere by the chimney of the power plant.

The waste heat of circulating water in the system is used for sludge heating and air heating respectively. The first sludge heating is circulating cooling water to directly heat up the sludge in the sludge heater 1, and the first air heating is in the air-water heat exchanger. The circulating water in 9 heats the air; the drying medium in the system - the hot air is sent to the air-water heat exchanger 9 by the blower, and exchanges heat with the circulating water entering it, and the air is heated for the first time; in the solar collector plate 6, the air The second heating is carried out under the action of solar energy.

The system of the utility model is also applicable to thermal power units with direct current water supply. The difference is that the circulating cooling water after the drying system is directly discharged into the rivers and oceans instead of the cooling tower 10. The rest of the system is the same, so it is not detailed here. stated.

Claims (1)

1. a system of utilizing the dry municipal sludge of power station recirculated water coupled solar, is characterized in that comprising carbonated drink, air and mud three flow processs; Described carbonated drink flow process contains: a condenser (7), recirculated water, water channel outlet that its water channel import connects Cooling Tower of Power Station (10) output are divided into two-way: a road is through air-to-water heat exchanger (9), an other road through mud well heater (1), and two-way finally all accesses in the original recirculated water circulating line of power plant and sends back in cooling tower (10); The exhaust steam that condenser (7) hot vapour source ejects from steam turbine (4); Described air flow process contains: a gas blower (8), air is delivered to heat exchanger (9) and solar heat-collection plate (6) successively through pipeline and heat laggard fluidized bed dryer (2) the heating mud that enters, finally by crossing fly-ash separator (5), by chimney, enter atmosphere after reaching emission standard; Described mud flow process contains: after the mud of pulverizing through pulverizer enters mud well heater (1), fall into fluidized bed type drier (2) and finally by belt conveyor, be transported to feed bin (3).