WO2021128105A1

WO2021128105A1 - Gas boiler flue gas depluming treatment system for municipal sludge drying and incineration treatment

Info

Publication number: WO2021128105A1
Application number: PCT/CN2019/128478
Authority: WO
Inventors: 张鹏
Original assignee: 深圳市能源环保有限公司
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2021-07-01

Abstract

A gas boiler flue gas depluming treatment system for municipal sludge drying and incineration treatment: due to the addition of an automatic smoke temperature regulation apparatus (2) with PID regulation, the automatic smoke temperature regulation apparatus (2) with PID regulation comprising a TIC temperature measurement display thermocouple (2.2) and a smart control module (2.1), and the TIC temperature measurement display thermocouple (2.2) being arranged at a chimney outlet, after the measured flue gas temperature is inputted into the smart control module (2.1), the smart control module (2.1) controls a steam system (1) to adjust the openness of a pneumatic regulating valve (1.2) such that steam enters a flue gas-steam heat exchanger (4) via a pipeline and performs heat exchange with the flue gas, and is then discharged via a drainage system (6), and the flue gas performs heat exchange with the steam at a chimney inlet via the flue gas-steam heat exchanger (4) so that the temperature further rises to implement depluming, and is then discharged from the chimney outlet. The system can be automatically regulated throughout the entire process without the need for manual intervention, and can effectively solve the problem of "white plumes" in existing sludge drying and incineration treatment.

Description

Gas boiler flue gas de-whitening treatment system for municipal sludge drying and incineration treatment

Technical field

The invention relates to a gas boiler flue gas bleaching treatment system, in particular to a gas boiler flue gas bleaching treatment system for municipal sludge drying and incineration treatment.

Background technique

In the municipal sludge drying and incineration treatment, gas-fired boilers need to be used to provide auxiliary steam sources for sludge drying and incineration. After the gas boiler uses natural gas for combustion, the products are H ₂ O and CO ₂ , and the moisture in the flue gas exists in the flue gas in a gaseous state. In order to improve the thermal efficiency of gas-fired boilers, economizers and air preheaters are arranged in the boiler flue, and the exhaust gas temperature can be reduced by 60-70°C. During operation, it was detected that the flue gas at the outlet of the air preheater had high humidity, and the flue gas contained water mist or tiny water droplets. When the flue gas is discharged through the chimney, the wet flue gas is more likely to condense into tiny droplets and become misty water vapor when it encounters a lower temperature environment. After the blue sky or the background color of clear mountains and green trees, the chimney exit appears "white plume" , Causing visual pollution, causing resentment and frequent complaints from surrounding residents. In view of the above shortcomings, the traditional treatment method is to install a steam-flue gas heat exchanger at the tail of the boiler to heat the flue gas, and only by increasing the exhaust gas temperature to solve the "white plume" problem. However, only by increasing the exhaust gas temperature, on the one hand, more steam needs to be consumed. On the other hand, the problem of "white plume" is still not completely solved due to the presence of water mist or tiny water droplets in the flue gas.

Summary of the invention

In order to solve the existing technical problems, the present invention proposes a gas boiler flue gas de-whitening treatment system for municipal sludge drying and incineration. Due to the addition of an automatic flue gas temperature adjustment device with PID adjustment, the PID-adjusted flue gas temperature automatically The adjustment device includes a TIC temperature measurement and display thermocouple and an intelligent control module. The TIC temperature measurement and display thermocouple is set at the chimney exit, and the TIC temperature measurement and display thermocouple inputs the measured flue gas temperature to the intelligent control module. The intelligent control module controls the steam system to adjust the opening of the pneumatic regulating valve. On the one hand, the steam enters the flue gas-steam heat exchanger through the pipe and exchanges heat with the flue gas, and then is discharged through the drainage system; on the other hand, the flue gas After heat exchange with steam through the flue gas-steam heat exchanger at the entrance of the chimney, the temperature is further increased to achieve de-whitening, and then it is discharged from the chimney outlet. The system can automatically adjust the whole process without manual intervention, and can effectively solve the "white plume" problem existing in the existing sludge drying and incineration treatment.

The technical solution proposed by the present invention to solve the technical problem is a gas boiler flue gas de-whitening treatment system for municipal sludge drying and incineration, including a steam system and a flue gas-steam heat exchanger arranged at the entrance of the chimney, and Including the drainage system set after the flue gas-steam heat exchanger. The steam system includes the front stop valve of the regulating valve, the pneumatic regulating valve, the rear stop valve of the regulating valve, the regulating valve bypass stop valve and the steam pipeline. The drainage system includes the front of the trap The stop valve, the steam trap, the rear stop valve of the steam trap, the bypass stop valve of the steam trap and the drain pipe are characterized in that an automatic smoke temperature adjustment device with PID adjustment is also installed, and the PID adjustment automatic smoke temperature adjustment device includes TIC temperature measurement and display thermocouple and intelligent control module, the TIC temperature measurement display thermocouple is set at the chimney exit, the TIC temperature measurement display thermocouple inputs the measured flue gas temperature into the intelligent control module, and the intelligent control module The control module controls the steam system to adjust the opening of the pneumatic regulating valve; on the one hand, after the steam enters the flue gas-steam heat exchanger through the pipeline and exchanges heat with the flue gas, the drain generated after the steam is cooled is discharged through the drain system; On the one hand, after the flue gas exchanges heat with steam through a flue gas-steam heat exchanger at the entrance of the chimney, the temperature is further increased to achieve de-whitening, and then discharged from the chimney outlet.

The preferred solution of the present invention is that the inlet of the flue gas-steam heat exchanger is also equipped with a demister to separate the tiny water droplets or water mist in the flue gas in advance, which greatly reduces the heat exchange requirements of the flue gas-steam heat exchanger The amount of steam.

The beneficial effects of the present invention: a gas boiler flue gas de-whitening treatment system for municipal sludge drying and incineration treatment, including a steam system and a flue gas-steam heat exchanger arranged at the entrance of the chimney, and also including a flue gas-steam heat exchanger arranged at the inlet of the chimney The drainage system after the steam heat exchanger is characterized in that an automatic smoke temperature adjustment device with PID adjustment is also added. The PID adjustment smoke temperature automatic adjustment device includes a TIC temperature measurement and display thermocouple and an intelligent control module. The TIC temperature measurement shows that the thermocouple is set at the chimney exit. After the TIC temperature measurement shows that the thermocouple inputs the measured temperature to the intelligent control module, the intelligent control module controls the opening of the pneumatic regulating valve of the steam system. On the one hand, the steam enters the flue gas-steam heat exchanger through the pipe and is discharged through the drainage system after heat exchange; on the other hand, the flue gas is exchanged with the steam through the flue gas-steam heat exchanger at the entrance of the chimney The temperature is further increased to achieve de-whitening, and then discharged from the chimney outlet. It can effectively solve the "white plume" problem existing in the existing sludge drying and incineration treatment. The system is automatically adjusted throughout the process without manual intervention.

Description of the drawings

Figure 1 and Figure 2 are schematic diagrams of the first implementation of the present invention. Figure 1 is a schematic diagram of the overall structure, and Figure 2 is a schematic diagram of flue gas de-whitening (the relationship between exhaust gas temperature and flue gas molar humidity).

3 and 4 are schematic diagrams of the structure of the second embodiment proposed by the present invention. Figure 3 is a schematic diagram of the overall structure, and Figure 4 is a schematic diagram of a partial structure (a schematic diagram of the principle of a demister).

In the picture:

1 Steam system, 1.1 front stop valve of regulating valve, 1.2 pneumatic regulating valve, 1.3 rear stop valve of regulating valve, 1.4 regulating valve bypass stop valve, 1.5 steam pipeline;

2 Smoke temperature automatic adjustment device with PID adjustment, 2.1 intelligent control module, 2.2 TIC temperature measurement and display thermocouple;

3 Demister;

4 Flue gas-steam heat exchanger;

5 U-shaped drainage pipe;

6 trap system, 6.1 trap front stop valve, 6.2 trap, 6.3 trap rear stop valve, 6.4 trap bypass stop valve, 6.5 trap piping.

Detailed ways

Figure 1 and Figure 2 are schematic diagrams of the first implementation of the present invention. Figure 1 is a schematic diagram of the overall structure, and Figure 2 is a schematic diagram of flue gas de-whitening (the relationship between exhaust gas temperature and flue gas molar humidity). The figure shows that in this example, a gas boiler flue gas de-whitening treatment system for municipal sludge drying and incineration treatment includes a steam system 1 and a flue gas-steam heat exchanger 4 arranged at the entrance of the chimney, and also includes a set The drainage system 6 after the flue gas-steam heat exchanger 4 is characterized in that an automatic smoke temperature adjustment device 2 with PID adjustment is also installed. The PID adjustment smoke temperature automatic adjustment device 2 includes a TIC temperature measurement display thermocouple 2.2 And intelligent control module 2.1, TIC temperature measurement display thermocouple is set at the chimney exit, TIC temperature measurement display thermocouple 2.2 input the measured flue gas temperature to the intelligent control module 2.1, the intelligent control module 2.1 controls the aerodynamics of the steam system 1 Adjust the opening of valve 1.2.

As shown in Fig. 1, the steam system 1 includes the front stop valve 1.1 of the regulating valve, the pneumatic regulating valve 1.2, the rear stop valve 1.3 of the regulating valve, the regulating valve bypass stop valve 1.4 and the steam pipeline 1.5. The trap system 6 includes a trap front stop valve 6.1, a trap 6.2, a trap rear stop valve 6.3, a trap bypass stop valve 6.4, and a trap 6.5.

In this embodiment, on the one hand, after the steam enters the flue gas-steam heat exchanger 4 through the pipe and exchanges heat with the flue gas, the drain generated after the steam is cooled is discharged through the drainage system 6; on the other hand, the flue gas is at the inlet of the chimney After entering the flue gas-steam heat exchanger 4 for heat exchange with steam, the temperature is further increased to achieve de-whitening, and then discharged from the chimney outlet.

Figure 2 is a schematic diagram of flue gas de-whitening (the relationship between exhaust gas temperature and flue gas molar humidity). The figure shows:

First, in this embodiment, the de-whitening process is A→E→F→C→D, and additional latent heat of vaporization needs to be consumed during the heating process of the flue gas and water mist mixture in the A→E section. The automatic flue temperature adjustment device with PID adjustment 2 automatically adjusts the required flue temperature according to the enthalpy diagram, eliminating the visual pollution caused by the white plume at the chimney exit, thereby avoiding the resentment and complaints of surrounding residents, and is beneficial to enterprise production Continuous and stable operation.

Second, the temperature of the flue gas is increased after passing through the flue gas-steam heat exchanger 4, and the actual operating point is far away from and below the 100% relative humidity line, and the flue gas will not enter the enthalpy-humidity diagram during the diffusion process of the flue gas in the chimney and outlet. White smoke area”, so as to ensure that no white plume will be generated. As shown in the schematic diagram of flue gas de-whitening in Figure 2, this embodiment is the section E→F→C→D.

Third, according to the ambient temperature and humidity, in order to ensure that no white plume will be generated, the TIC temperature measurement display thermocouple 2.2 measures the outlet flue gas temperature and transmits the temperature data to the intelligent control module 2.1, which controls the pneumatic adjustment by the intelligent control module 2.1 The opening of valve 1.2 is used to adjust the steam supply. The system is automatically adjusted throughout the process without manual intervention.

3 and 4 are schematic diagrams of the structure of the second embodiment proposed by the present invention. Figure 3 is a schematic diagram of the overall structure, and Figure 4 is a schematic diagram of a partial structure (a schematic diagram of the principle of a demister). The difference from the first embodiment is that, as shown in the figure, in this example, a mist eliminator 3 is also installed at the inlet of the flue gas-steam heat exchanger 4. The mist eliminator 3 is used to separate tiny water droplets or water mist in the flue gas in advance, which greatly reduces the amount of steam required by the flue gas-steam heat exchanger 4 for heat exchange.

After the flue gas with higher humidity passes through the demister 3, the tiny water droplets or water mist in the flue gas are separated under the action of centrifugal force due to the density difference, and collected by the water mist collector of the demister 3, and then concentrated through the U-shaped drain pipe 5. discharge. Compared with the prior art, because the mist eliminator 3 is installed, the water mist in the flue gas is heated to avoid the need to absorb the latent heat of vaporization, thereby reducing the consumption of heating steam and improving the energy-saving effect. After passing through the mist eliminator 3, the flue gas approaches and is on the 100% relative humidity line, as shown in the principle diagram of flue gas de-whitening in FIG.

The demister includes a stainless steel baffle, a water mist collector, and a U-shaped discharge pipe. A water droplet collection tank is also provided at the bottom of the demister to facilitate timely discharge of the water droplets separated by centrifugation. Figure 4 is a schematic diagram of the defogging principle of the defogger. The figure shows that there are three turning channels in the demister. After the supersaturated flue gas passes through the demister, the specific gravity of the water mist is relatively large. Due to the centrifugal force, the water mist is gradually thrown on the outer wall of the curve. A water film is formed, and after accumulation, water droplets flow into the bottom water droplet collection tank.

In this embodiment, the demister 3 pre-dehydrates the flue gas, and the flue gas after dehydration enters the flue gas-steam heater for heating. The entire de-whitening process is A→B→C→D, and the required heating temperature Compared with the first embodiment, it is about 20°C lower, which saves steam consumption, and the demister 3 exerts an energy-saving effect. The automatic smoke temperature adjustment device with PID adjustment 2 automatically adjusts the required smoke temperature according to the relationship between the exhaust temperature and the molar humidity of the smoke (Figure 2), which completely eliminates the visual pollution caused by the white plume at the exit of the chimney. Avoiding resentment and complaints from surrounding residents is conducive to the continuous and stable operation of enterprise production.

Claims

A gas boiler flue gas de-whitening treatment system for municipal sludge drying and incineration, including a steam system and a flue gas-steam heat exchanger arranged at the entrance of the chimney, and also comprising a flue gas-steam heat exchanger arranged after the flue gas-steam heat exchanger Drain system, steam system includes front stop valve of regulating valve, pneumatic regulating valve, rear stop valve of regulating valve, regulating valve bypass stop valve and steam pipeline. Draining system includes front stop valve of steam trap, steam trap, rear stop valve of steam trap, The steam trap bypass stop valve and the drain pipe are characterized in that an automatic smoke temperature adjustment device with PID adjustment is also installed. The PID adjustment smoke temperature automatic adjustment device includes a TIC temperature measurement and display thermocouple and an intelligent control module. The TIC temperature measurement shows that the thermocouple is set at the exit of the chimney. After the TIC temperature measurement shows that the thermocouple inputs the measured flue gas temperature to the intelligent control module, the intelligent control module controls the steam system to adjust the pneumatic control valve. Opening degree; on the one hand, after the steam enters the flue gas-steam heat exchanger through the pipe to exchange heat with the flue gas, the drain generated after the steam is cooled is discharged through the drainage system; on the other hand, the flue gas passes through the flue gas at the entrance of the chimney -After the steam heat exchanger exchanges heat with the steam, the temperature is further increased to achieve de-whitening, and then discharged from the chimney outlet.
The gas boiler flue gas de-whitening treatment system for municipal sludge drying and incineration according to claim 1, wherein the inlet of the flue gas-steam heat exchanger is also equipped with a demister to separate out in advance The tiny water droplets or water mist in the flue gas greatly reduce the amount of steam required for heat exchange in the flue gas-steam heat exchanger.