CN215637204U

CN215637204U - Waste incineration flue gas waste heat utilization system

Info

Publication number: CN215637204U
Application number: CN202121743205.0U
Authority: CN
Inventors: 管志云; 李才; 刘玉坤
Original assignee: Shanghai Institute for Design and Research on Environmental Engineering Co Ltd
Current assignee: Shanghai Institute for Design and Research on Environmental Engineering Co Ltd
Priority date: 2021-07-29
Filing date: 2021-07-29
Publication date: 2022-01-25
Anticipated expiration: 2031-07-29

Abstract

The utility model discloses a waste incineration flue gas waste heat utilization system which comprises a feed hopper, an incinerator, a waste heat boiler, a semi-dry reaction tower, a bag-type dust remover, an induced draft fan, a chimney and a hot water circulating system, wherein the feed hopper, the incinerator, the waste heat boiler, the semi-dry reaction tower, the bag-type dust remover, the induced draft fan and the chimney are sequentially arranged, the hot water circulating system is a loop formed by a secondary low-temperature economizer, a primary low-temperature economizer, a hot water circulating pump and a warm air fan, waste heat recovery is carried out on flue gas discharged by the waste heat boiler through two-stage heat exchange, the recovered heat is used for preheating primary air, waste heat of high-temperature flue gas is effectively recovered, and the heat efficiency of a whole plant is improved.

Description

Waste incineration flue gas waste heat utilization system

Technical Field

The utility model belongs to the technical field of waste heat utilization, and particularly relates to a waste incineration flue gas waste heat utilization system.

Background

As shown in fig. 1, the schematic diagram of a waste incineration flue gas treatment system of an existing power plant includes a feeding hopper 1, an incinerator 2, an exhaust-heat boiler 3, a semi-dry reaction tower 4, a bag-type dust collector 5, an induced draft fan 6 and a chimney 7 which are sequentially arranged, waste used for incineration power generation enters the incinerator 2 from the feeding hopper 1 to be incinerated, the incinerated flue gas enters the exhaust-heat boiler 3 from the incinerator 2 to be subjected to heat recovery, the temperature is about 220 ℃ when the waste gas is discharged out of the exhaust-heat boiler 3, and the waste gas is desulfurized through the semi-dry reaction tower 4 and is discharged to the atmosphere through the induced draft fan 6 after the dust is removed by the bag-type dust collector 5.

The outlet smoke temperature of the waste heat boiler 3 is 220 ℃, the smoke temperature required by the semi-dry reaction tower 4 can meet the requirement as long as the smoke temperature is not lower than 180 ℃, the heat is not recovered in the existing waste incineration power generation system, so that the smoke with huge heat is directly discharged to the atmosphere from the chimney 7, on one hand, huge energy waste is caused, and on the other hand, the discharged smoke temperature is higher, so that great adverse effect is brought to the environment.

At present, the way of utilizing the waste heat of the flue gas is mainly that a waste heat boiler 3 is adopted to generate high-temperature high-pressure steam to drive a steam turbine to generate electricity, but the way also releases a large amount of high-temperature flue gas, and the overhigh exhaust temperature reduces the thermal efficiency of the whole plant. Therefore, the recovery of heat from the boiler exhaust gas as much as possible, the improvement of the thermal efficiency of the power plant and the operation economy are worthy of intensive research in the field of waste incineration power generation.

On the other hand, as shown in fig. 1, after the air required for burning the garbage is extracted from above the garbage pit 10 by the primary air fan 8, the air is preheated by the primary air preheater 9 before entering the incinerator 2, and a large amount of heat energy is consumed in the process.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects brought by the prior art and provide a waste incineration flue gas waste heat utilization system which has high heat energy utilization rate, can effectively recover heat in flue gas and improve the heat efficiency of the whole plant.

In order to achieve the purpose, the utility model adopts the following technical scheme:

the utility model provides a waste incineration flue gas waste heat utilization system, is including the feeder hopper that sets gradually, burns burning furnace, exhaust-heat boiler, half dry reaction tower, sack cleaner, draught fan to and the chimney, still include hot water circulating system for the waste heat of the flue gas of utilizing by exhaust-heat boiler exhaust preheats burning required air.

The hot water circulating system is a loop consisting of a second-stage low-temperature economizer, a first-stage low-temperature economizer, a hot water circulating pump and a warm air blower, wherein:

the secondary low-temperature economizer is positioned between the waste heat boiler and the semi-dry reaction tower and is used for exchanging heat with the flue gas discharged by the waste heat boiler;

the primary low-temperature economizer is positioned between the bag dust collector and the induced draft fan and is used for exchanging heat with the flue gas discharged by the bag dust collector;

the fan heater is positioned on a line for conveying air required by incineration to the incinerator and is used for carrying out heat exchange with air extracted from the upper part of the garbage pit;

the hot water circulating pump is connected to the circulating loop and used for providing power for circulating water in the system.

Preferably, the hot water circulating pump is communicated between the warm air blower and the first-stage low-temperature economizer.

Furthermore, a primary air preheater and a primary fan are sequentially arranged on a line for conveying air extracted from the upper part of the garbage pit to the incinerator, and the fan heater is positioned in front of the primary air preheater.

Furthermore, the flue at the outlet of the primary low-temperature economizer is in the form of glass flakes subjected to anti-corrosion treatment.

This waste incineration flue gas waste heat utilization system adds a hot water circulating system on current waste incineration flue gas processing system, carries out waste heat recovery through the two-stage heat exchange to exhaust flue gas of waste heat boiler to be used for preheating of a wind with the heat of retrieving, constituted waste incineration flue gas waste heat utilization system, reduced the energy consumption of a wind air preheater, retrieved the waste heat of high temperature flue gas effectively, improved the thermal efficiency of whole factory.

Drawings

Fig. 1 is a schematic structural diagram of a conventional waste incineration flue gas treatment system.

FIG. 2 is a schematic structural diagram of a waste incineration flue gas waste heat utilization system of the present invention.

Fig. 3 is a schematic structural view of a hot water circulation system according to the present invention.

Description of the figure numbers: 1-a feed hopper; 2-an incinerator; 3, a waste heat boiler; 4-a semi-dry reaction tower; 5-bag dust collector; 6-induced draft fan; 7-a chimney; 8-a primary air fan; 9-primary air pre-heater; 10-a garbage pit; 100-two-stage low-temperature economizer; 101-first-stage low-temperature economizer; 102-a warm air blower; 103-hot water circulating pump.

Detailed Description

The present invention is further described in detail with reference to the drawings and examples, but the following examples are only illustrative and not intended to limit the scope of the present invention, and any changes or substitutions based on the present invention shall fall within the protection scope of the present invention.

As shown in fig. 2, the waste incineration flue gas waste heat utilization system of the present invention includes a feeding hopper 1, an incinerator 2, a waste heat boiler 3, a semi-dry reaction tower 4, a bag-type dust collector 5, an induced draft fan 6, a chimney 7, and a hot water circulation system, which are sequentially disposed, so as to fully utilize the waste heat of the flue gas discharged from the waste heat boiler 3, preheat the air required for incineration, and reduce the energy consumption required for preheating the existing air.

Referring to fig. 3, the hot water circulation system is a loop formed by a two-stage low-temperature economizer 100, a one-stage low-temperature economizer 101, a hot water circulation pump 103 and a heater 102, wherein:

the secondary low-temperature economizer 101 is positioned between the waste heat boiler 3 and the semi-dry reaction tower 4 and is used for exchanging heat with the flue gas discharged by the waste heat boiler 3; specifically, the flue gas discharged by the exhaust-heat boiler 3 passes through the heat release side of the secondary low-temperature economizer 101, exchanges heat with circulating water at the heat absorption side of the secondary low-temperature economizer 101, and then enters the semi-dry reaction tower 4;

the primary low-temperature economizer 100 is positioned between the bag dust collector 5 and the induced draft fan 6 and is used for exchanging heat with the flue gas discharged by the bag dust collector 5; specifically, the flue gas discharged by the bag dust collector 5 passes through the heat-releasing side of the primary low-temperature economizer 100, exchanges heat with circulating water at the heat-absorbing side of the primary low-temperature economizer 100, and then is led to the induced draft fan 6;

the warm air blower 102 is positioned on a line for conveying air required by incineration to the incinerator and is used for carrying out heat exchange with air extracted from the upper part of the garbage pit 10;

the hot water circulating pump 103 is connected to the circulating loop and used for providing power for circulating water in the system. Preferably, the hot water circulation pump 103 is communicated between the warm air blower 102 and the primary low-temperature economizer 101.

Further, a primary air preheater 9 and a primary air blower 8 are sequentially arranged on a line for conveying air extracted from the upper side of the garbage pit 10 to the incinerator 3, and the warm air blower 102 is located in front of the primary air preheater 9 and is communicated with the garbage pit 10 and the primary air preheater 9, so that hot circulating water from the secondary low-temperature economizer 100 heats air at the heat absorption side of the warm air blower 102 at the heat emission side of the warm air blower 102, and energy consumption required by the primary air preheater 9 for heating the air is reduced.

Furthermore, the heat exchange materials of the first-stage low-temperature economizer 101 and the second-stage low-temperature economizer 102 are fluoroplastics, and the materials can effectively avoid corrosion caused by cooling of flue gas.

Furthermore, the flue at the outlet of the primary low-temperature economizer 101 is subjected to anticorrosive treatment and can adopt forms such as glass flakes.

The working process of the waste incineration flue gas waste heat utilization system of the embodiment is as follows:

working process of the hot water circulating system: the working pressure of the circulating water is 0.3MPa, the circulating water circularly runs in a waste incineration flue gas waste heat utilization system, and firstly enters the heat absorption side of the primary low-temperature economizer 101, the temperature of the inlet water is about 40 ℃, and the temperature of the outlet water is 110 ℃. The hot circulating water heated by the first-stage low-temperature economizer 101 enters the heat absorption side of the second-stage low-temperature economizer 100 again, and the outlet water temperature is 150 ℃. The hot circulating water after secondary heating enters the heat release side of the fan heater 102 to heat primary air, the water outlet temperature of the circulating water from the fan heater 102 is 40 ℃, and then the circulating water enters the primary low-temperature economizer 101 through the hot water circulating pump 103, and the circulation is repeated.

The working process of the flue gas is as follows: the temperature of the flue gas at the outlet of the waste heat boiler 3 is about 220 ℃, the flue gas firstly enters the heat-releasing side of the secondary low-temperature economizer 100, the temperature of the flue gas at the outlet is reduced to about 180 ℃, the requirement of the temperature of the flue gas inlet of the semi-dry reaction tower 4 being not lower than 180 ℃ is met, and the flue gas passes through the semi-dry reaction tower 4 and the bag-type dust collector 5 in sequence. The smoke temperature of the smoke at the outlet of the bag-type dust collector 5 is about 150 ℃, and then the smoke enters the primary economizer 101 to further reduce the smoke temperature to about 110 ℃. And finally, the flue gas enters a draught fan 6 and then is discharged into a chimney 7.

This waste incineration flue gas waste heat utilization system adds a hot water circulating system on current waste incineration flue gas processing system, carries out waste heat recovery through the two-stage heat exchange to exhaust flue gas of exhaust-heat boiler 3 to be used for preheating of a wind with the heat of retrieving, constituted waste incineration flue gas waste heat utilization system, reduced the energy consumption of a wind air preheater 9, retrieved the waste heat of high temperature flue gas effectively, improved the thermal efficiency of whole factory.

Claims

1. A waste incineration flue gas waste heat utilization system comprises a feed hopper, an incinerator, a waste heat boiler, a semi-dry type reaction tower, a bag-type dust remover, an induced draft fan and a chimney which are sequentially arranged, and is characterized by further comprising a hot water circulating system for preheating air required by incineration by using waste heat of flue gas discharged by the waste heat boiler;

2. The waste incineration flue gas waste heat utilization system according to claim 1, wherein the hot water circulating pump is communicated between the warm air blower and the primary low-temperature economizer.

3. The waste incineration flue gas waste heat utilization system according to claim 1, wherein a primary air preheater and a primary air blower are sequentially arranged on a line for conveying air extracted from above the waste pit to the incinerator, and the fan heater is located in front of the primary air preheater.

4. The waste incineration flue gas waste heat utilization system according to claim 1, wherein a flue at an outlet of the primary low-temperature economizer is in the form of glass flakes subjected to corrosion prevention treatment.