1. A high-parameter waste incineration waste heat boiler is characterized in that a smoke inlet hearth, a high-temperature flue, a smoke turning chamber, a high-temperature ceramic filter, a smoke connecting chamber, a high-temperature heat exchange region, a smoke chilling region, a low-temperature heat exchange region and a smoke circulating system are sequentially arranged along the smoke flowing direction; the smoke inlet hearth is connected with the outlet of the incinerator, the unburned combustible gas continues to burn in the hearth, and the inner wall of the hearth is coated with a refractory material.

2. The high-parameter waste incineration waste heat boiler according to claim 1, characterized in that: the smoke inlet hearth, the high-temperature flue, the smoke turning chamber, the high-temperature ceramic filter, the smoke connecting chamber, the high-temperature heat exchange region and the smoke chilling region are all surrounded by a water-cooled wall structure, and the high-temperature ceramic filter and the low-temperature heat exchange region are surrounded by enclosing plates.

3. The high-parameter waste incineration waste heat boiler according to claim 2, characterized in that: and a primary high-temperature pass/reheater and a secondary high-temperature pass/reheater are arranged in the high-temperature heat exchange zone, and the high-temperature pass/reheaters are arranged in parallel along the width direction of the hearth and are arranged in series along the height of the hearth.

4. The high-parameter waste incineration waste heat boiler according to claim 3, characterized in that: a medium temperature pass/reheater and a water-cooling evaporator are arranged behind the smoke chilling zone; and a coal economizer is arranged in the low-temperature heat exchange area and is arranged in a segmented mode.

5. The high-parameter waste incineration waste heat boiler according to claim 4, characterized in that: heating surface soot blowers are arranged in the high-temperature heat exchange area and the low-temperature heat exchange area to ensure the cleanliness of the heating surface.

6. The high-parameter waste incineration waste heat boiler according to claim 5, characterized in that: the inlet positions of the high-temperature ceramic filter and the flue gas chilling zone are both provided with a flue gas recirculation inlet, the temperature range of the flue gas inlet of the high-temperature ceramic filter is 900-1000 ℃, the temperature of the flue gas outlet of the secondary high-temperature pass/reheater is higher than 750 ℃, and the temperature of the flue gas outlet after the flue gas chilling zone after being chilled by recirculated flue gas is not more than 650 ℃.

7. The high-parameter waste incineration waste heat boiler according to claim 6, characterized in that: the method is characterized in that: when the load is more than or equal to 85% of the maximum continuous evaporation capacity of the boiler, the flue gas recycling inlet selects the purified flue gas, and when the load is less than 85% of the maximum continuous evaporation capacity of the boiler, the flue gas recycling inlet selects the unpurified flue gas at the outlet of the economizer.

8. The high parameter waste incineration waste heat boiler of claim 7, wherein: the flue gas turn to the room and arrange for the U type, the flue gas turns to and is equipped with a plurality of circulation flue gas spouts in room and the flue gas connecting chamber, the spout is arranged along furnace width direction multirow, circulation flue gas gets into the flue with the form of hedging.

9. The high-parameter waste incineration waste heat boiler according to claim 1, characterized in that: and a CaO powder nozzle is arranged at the position of the ceiling corresponding to the smoke outlet of the high-temperature flue, and an ash bucket is arranged at the lower end of the smoke turning chamber.

10. The high-parameter waste incineration waste heat boiler according to claim 1, characterized in that: the smoke connecting chamber is connected with the adjacent parts by adopting expansion joints, and the smoke flowing direction and the horizontal direction form an included angle which ranges from 15 degrees to 60 degrees.

Background

The biomass power generation is one of renewable energy power generation, and belongs to a clean power generation technology. The biomass power generation can replace a coal-fired thermal power plant to a certain extent, and double benefits of economy and environment are realized. Among them, the garbage incineration power generation can realize the reduction, harmlessness and reclamation of garbage disposal, and is the mainstream technology of municipal solid waste disposal in China. However, since the municipal solid waste contains a large amount of alkali metals (Na, K, etc.) and chlorine (Cl), a low-melting alkali metal salt and a corrosive gas such as HCl are generated in the flue gas after combustion. With the continuous improvement of main steam parameters, the substances can seriously corrode a high-temperature heating surface, and the service life and the safe operation time of the equipment are reduced. The main reason that the main steam parameter of the current garbage generator set is mostly lower than 6.5MPa/450 ℃ is also the main reason. However, as the investment and post-operating costs of power plants increase, the thermal efficiency and economic efficiency of power plants become more and more of a concern. Although the corrosion of the heating surface can be alleviated to some extent by using new corrosion-resistant high-temperature materials or coatings, they are economically expensive. In addition, the high-temperature ceramic filter has a wide application temperature range, the temperature can reach 900-; the flue gas temperature application scope is wider, and dust collection efficiency is steady. Therefore, designing a high-parameter incineration waste heat boiler capable of effectively inhibiting high-temperature corrosion and preventing alkali metal from depositing ash on a heated surface is a development direction of waste heat recovery of a waste incineration power plant in the future.

Disclosure of Invention

The technical problem to be solved by the invention is the problem in the prior art.

In order to solve the technical problems, the technical scheme of the invention is to provide a high-parameter waste incineration waste heat boiler (6.5-22.1MPa), and the gradient utilization of the flue gas energy is realized by reasonably arranging high-temperature heating surfaces such as a pass/reheater and the like and medium-low temperature heating surfaces such as an economizer and the like according to the difference of the flue gas temperature. Meanwhile, a high-temperature ceramic filtering device, flue gas recirculation and alkaline substance injection are needed to effectively inhibit high-temperature corrosion and prevent the problems of alkali metal dust deposition on a heated surface and the like. Finally, safe and effective operation of high steam parameters, high system heat efficiency and a heating surface is realized.

The high-parameter waste heat boiler sequentially comprises a flue gas inlet hearth, a high-temperature flue, a flue gas turning chamber, a high-temperature ceramic filter, a flue gas connecting chamber, a high-temperature heat exchange region, a flue gas chilling region, a low-temperature heat exchange region and a flue gas circulating system along the flow direction of flue gas. The high-temperature ceramic filter and the low-temperature heat exchange region are surrounded by surrounding plates. The flue gas inlet hearth is connected with an outlet of the incinerator, and the inner wall of the flue gas inlet hearth is coated with a refractory material so as to ensure the safety of the water-cooled wall. The high-temperature heat exchange zone is provided with a first-stage high-temperature pass/reheater and a second-stage high-temperature pass/reheater, and the high-temperature pass/reheaters are arranged in parallel along the width direction of the hearth and arranged in series along the height of the hearth. A middle-temperature pass/reheater and a water-cooling evaporator are arranged behind the smoke chilling zone. And the coal economizer is arranged in the low-temperature heat exchange area in a sectional manner. And a CaO powder nozzle is arranged at the position of the ceiling corresponding to the smoke outlet of the high-temperature flue, and an ash hopper is arranged at the lower end of the smoke turning chamber. And a flue gas recirculation inlet is arranged at the inlet of the high-temperature ceramic filter and the flue gas chilling zone. The flue gas circulating system is mainly used for adjusting and controlling the outlet flue gas temperature of the high-temperature ceramic filter and the flue gas chilling zone, wherein a flue gas recirculation inlet at the inlet of the high-temperature ceramic filter is used for adapting to the large fluctuation of the flue gas temperature caused by the severe change of load blending fuel of a hearth so as to ensure the safe operation of the high-temperature ceramic filter; the flue gas recirculation inlet at the inlet of the flue gas chilling zone is used for chilling the inlet temperature of the medium-temperature heat exchange zone so as to avoid the desublimation zone of the alkali metal compound of 650-680 ℃, and eliminate the condensation, adhesion and fly ash accumulation of gaseous alkali metal salt on the medium-temperature heating surface; the temperature range of the flue gas inlet of the high-temperature ceramic filter is 900-1000 ℃, the temperature of the flue gas outlet of the secondary high-temperature filter/reheater is higher than 750 ℃, and the temperature of the flue gas outlet after the flue gas chilling zone is not more than 650 ℃ after the flue gas outlet is chilled by the recirculated flue gas.

Preferably, the high-temperature flue adopts an inverted U-shaped structure, the CaO nozzles are arranged on a ceiling and arranged in a plurality of rows along the width direction of the hearth, the flowing direction of the sprayed CaO powder is the same as that of the flue gas, and the flowing direction of the flue gas at the final outlet of the high-temperature flue is downward, so that the fly ash can be conveniently captured and collected.

Preferably, the flue gas flowing space formed by the flue gas inlet hearth and the high-temperature flue meets the restriction requirements of 2-2.5s of dioxin residence time and 850 ℃ higher than the temperature before a flue gas outlet;

preferably, the flue gas turning chamber is arranged in a U shape, a plurality of circulating flue gas nozzles are arranged in the flue gas turning chamber and the flue gas connecting chamber, the nozzles are arranged in a plurality of rows along the width direction of the hearth, and the circulating flue gas enters the flue in an opposite impact manner;

preferably, a circulating flue gas collecting box is arranged behind the nozzles on the front wall and the rear wall of the flue gas steering chamber, and the flow and momentum of the entering circulating flue gas are adjustable through the circulating flue gas collecting box and are used for adjusting and controlling the temperature and the speed of the flue gas entering the high-temperature ceramic filter;

preferably, the fan adopted by the circulating flue gas system adopts a variable frequency design, so that the flow and the speed of the circulating flue gas can be adjusted;

preferably, the temperature of the flue gas inlet of the high-temperature ceramic filter is selected to be 950 ℃, and the temperature of the flue gas outlet of the secondary high-temperature pass/reheater is higher than 750 ℃;

preferably, the first-stage high-temperature pass/reheater, the second-stage high-temperature pass/reheater and the flue gas in the high-temperature heat exchange zone are arranged in a concurrent flow manner;

preferably, the flue gas diversion chamber is connected with other components by adopting an expansion joint, and the flow direction of a flue gas outlet of the flue gas diversion chamber has an included angle with the horizontal, wherein the included angle is in the range of 15-60 degrees, so that the deposition of fly ash is prevented;

preferably, a middle temperature superheater/reheater and a water-cooling evaporator are installed in the back of the flue gas chilling zone, a superheater and a reheater in the middle temperature superheater/reheater are arranged in parallel along the width direction of the hearth, and the water-cooling evaporator and the middle temperature superheater/reheater are arranged in series along the flow direction of the flue gas and are both arranged in a countercurrent manner;

preferably, the temperature of the flue gas outlet after the flue gas chilling zone is not more than 650 ℃ after the flue gas is chilled by the recirculated flue gas;

preferably, when the load is more than or equal to 85% of the maximum continuous evaporation capacity of the boiler, the flue gas recycling inlet selects the purified flue gas, and when the load is less than 85% of the maximum continuous evaporation capacity of the boiler, the flue gas recycling inlet selects the unpurified flue gas at the outlet of the economizer 13.

Preferably, the economizer in the low-temperature heat exchange zone is arranged in a segmented mode and is arranged in a countercurrent series with the flue gas;

preferably, the amount of CaO used is calculated according to the content of HCl at the inlet of the high-temperature flue, and is used for reducing the content of acid gases such as HCl in the flue gas;

preferably, heating surface soot blowers are arranged in the high-temperature heat exchange area and the low-temperature heat exchange area to ensure the cleanliness of the heating surface;

preferably, fly ash collecting devices are arranged below the high-temperature flue outlet, the high-temperature heat exchange area and the low-temperature heat exchange area of the waste heat boiler.

The invention has the beneficial effects that:

the high-parameter waste heat recovery device has high system thermal efficiency, performs cascade utilization on the heat of the flue gas, largely uses high-temperature heating surfaces such as a superheater and a reheater in a high-temperature flue gas area, uses a corresponding medium-low temperature heating surface in a medium-low temperature flue gas area, improves the heat exchange efficiency and the steam quality, and reduces the investment on the medium-low temperature heating surface;

the flue gas recirculation body and the CaO are sprayed, so that high-temperature corrosion of a high-temperature heating surface and ash deposition of the heating surface caused by alkali metal can be effectively inhibited, the heating surface is always in a safe working range, the problems of high-temperature corrosion of the heating surface and ash deposition of the alkali metal caused by high main steam parameters are solved, and the running cost of equipment is reduced.

The high-temperature flue gas ceramic filter can effectively filter and capture fly ash in flue gas, improve the cleanliness of a subsequent heating surface, strengthen the heat transfer characteristic of the heating surface and improve the heat exchange efficiency.

The circulating flue gas system can effectively adjust and control the parameters of inlet flue gas entering the high-temperature flue gas filtering equipment, improve the change of heat exchange characteristics caused by load change, unstable combustion and fuel diversity of a unit, and ensure the safety of operation of boiler equipment and a subsequent heating surface.

Flue gas recirculation can respond quickly to changes in flue gas temperature and flow parameters relative to adjustments in combustion.

Drawings

FIG. 1 is a schematic structural view of a high-parameter waste incineration waste heat boiler provided by the invention;

FIG. 2 is a structural view of a high temperature ceramic filter, in which FIG. 2a is a schematic structural view and FIG. 2b is a schematic sectional view taken along line A-A of FIG. 2;

FIG. 3 is a schematic diagram of the arrangement of the circulating flue gas nozzles, FIG. 3a is a schematic diagram of the arrangement of the flue gas nozzles in the flue gas turning chamber, and FIG. 3b is a schematic diagram of the arrangement of the flue gas nozzles in the flue gas connecting chamber;

in FIGS. 1-3, 1-flue gas inlet furnace; 2-high temperature flue; 2-1-CaO powder nozzle; 2-2-high temperature flue outlet; 3-1-a fly ash collection device; 3-a flue gas diversion chamber; 4-a high temperature ceramic filter; 5-a flue gas connection chamber; 6-high temperature heat exchange zone; 7-a flue gas chilling zone; 8-a low temperature heat transfer zone; 9-first-stage high-temperature pass/reheater; 10-secondary high temperature pass/reheater; 11-low temperature superheater; 12-an evaporator; 13-a coal economizer; 14-flue gas recirculation inlet; 15-flue gas recirculation inlet; 16. 17-a fly ash collection device; 18-flue gas recirculation system; 19-circulating flue gas nozzles; 20-circulating flue gas collection box; 21-a flue gas outlet; 22-a ceramic filter element; 23-a high temperature ceramic filter housing; 24-a flue gas outlet; 25-high temperature ceramic filter inlet; 26-high pressure gas back-blowing nozzle; 27-high pressure gas inlet.

Detailed Description

In order to make the invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings.

Examples

Referring to fig. 1, the wide-load adjustable high-parameter waste incineration waste heat boiler of the invention sequentially comprises a gas inlet hearth 1, a high-temperature flue 2, a flue gas turning chamber 3, a high-temperature ceramic filter 4, a flue gas connecting chamber 5, a high-temperature heat exchange zone 6, a flue gas chilling zone 7, a low-temperature heat exchange zone 8 and a flue gas circulating system 18 along the flow direction of flue gas. The high-temperature ceramic filter 4 and the low-temperature heat exchange zone 8 are surrounded by surrounding plates. The flue gas inlet hearth 1 is connected with an outlet of the incinerator, and the inner wall of the flue gas inlet hearth is coated with refractory materials so as to ensure the safety of a water-cooled wall. The high-temperature heat exchange zone 6 is provided with a primary high-temperature pass/reheater 9 and a secondary high-temperature pass/reheater 10, and a middle-temperature pass/reheater 11 and a water-cooled evaporator 12 are arranged in the back of the flue gas chilling zone 7. The economizer 13 is arranged in the low-temperature heat exchange zone 8, and the economizer 13 is designed in a sectional arrangement mode. A CaO powder nozzle 2-1 is arranged at the position of the ceiling corresponding to the smoke outlet of the high-temperature flue 2, and an ash hopper 3-1 is arranged at the lower end of the smoke diversion chamber 3. The inlet positions of the high-temperature ceramic filter 4 and the flue gas chilling zone 7 are respectively provided with a flue gas recirculation inlet 14 and a flue gas recirculation inlet 15. The flue gas circulating system 18 is mainly used for adjusting and controlling the outlet flue gas temperature of the high-temperature ceramic filter 4 and the flue gas chilling zone 7, and the flue gas source of the flue gas circulating system 18 comprises flue gas from the outlet of an economizer or purified flue gas; the flue gas recirculation inlet 14 is used for adapting to the large fluctuation of the flue gas temperature caused by the severe change of the load blending fuel of the hearth so as to ensure the operation safety of the high-temperature ceramic filter 4; the flue gas recirculation inlet 15 is used for chilling the inlet temperature of the medium-temperature heat exchange zone 6 to avoid the desublimation zone (650 plus 680 ℃) of alkali metal compounds, and eliminating the condensation, adhesion and fly ash accumulation of gaseous alkali metal salt on the medium-temperature heating surface. The circulating flue gas enters the flue in a hedging mode, and the nozzles 20 are arranged in a plurality of rows along the width direction of the hearth. The fan used by the circulating flue gas system 18 adopts a variable frequency design, and the flow and speed of the circulating flue gas can be adjusted. The heating surface selects a proper soot blower according to different working conditions and positions so as to ensure the cleanliness of the heating surface.

The high temperature ceramic filter 4 is enclosed by a housing 23, and comprises a flue gas inlet 25, a core component ceramic filter element 22, a flue gas outlet 24, a high pressure gas blowback nozzle 26 for blowback of fly ash on the ceramic filter element 22, and an external high pressure gas inlet 27. The dust-containing flue gas enters the high-temperature ceramic filter 4 from the flue gas inlet 25, fly ash is collected on the filter element after passing through the ceramic filter element 22, and the filtered gas enters the subsequent flue gas flow path through the flue gas outlet 24. When the smoke pressure difference of the inlet and the outlet of the high-temperature ceramic filter 4 is larger than a set value, the high-pressure gas back-blowing nozzle 26 performs gas back-blowing, and fly ash on the filter element is back-blown and collected by the ash hopper 3-1 under the action of gravity.