Packing towers for thermal power plants, etc.

Abstract

We provide a gas cleaning device for packed towers in thermal power plants. [Solution] In an exhaust gas cleaning device for a packed tower or the like, water is flowed over the surface of a packing material with a large surface area, causing the gas to come into countercurrent contact at a low speed. Furthermore, the apparent gas velocity is 0.3 to 1.5 m / s (40 to 70% of the flooding velocity), and the water supply rate is 15 to 20 t / m³. 2 • h, liquid gas ratio 1-10 l / m 3 The optimal values ​​are a filling height of 2-5m and a pressure loss of 0.5kPa / m height (50mmAp / m height).

Description

Technical Field

[0001] The present invention relates to a packed tower in a thermal power plant. Since Japan was blessed with abundant water resources, power source development has focused on hydropower under the principle of mainly relying on hydropower and supplemented by thermal power. Around 1951, the growth rate of power demand has constantly exceeded 15%. To cope with this, the power supply has been enhanced by building state-of-the-art large-scale thermal power plants with significantly improved thermal efficiency, and stable power supply has been achieved through the completion of the power transmission network by constructing extra-high voltage power transmission lines. As a result, the relationship between mainly relying on hydropower and supplemented by thermal power has changed significantly. A packed tower gas scrubber (PACKED TOWER SCRUBBER) is a device that allows mass transfer and heat transfer between gas-liquid and liquid-gas. It is a tower filled with various packings PACKING in an empty tower. As packings, rock fragments and coke were used in the past, but various shapes and sizes of commercially available products are available, such as magnetic, metal Intalox (Metal Intalox) Figure 5B, Sulzer Paking (Sulzer Paking) Figure 6B, plastic Rasching Ring (Rasching Ring) Figure 6A, Intalox Saddle (Intalox Saddle) Figure 5A, etc. For packings, irregular packing is performed for those with large diameters, and regular packing is performed for those with large diameters.

Background Art

[0002] A conventional thermal power plant Figure 7(21) was a small-scale thermal power plant (steam power plant) with a capacity of 66 MW, 8.9 MPa (88 kgf / cm 2 ), and about 510 °C. Its thermal efficiency (thermal efficiency) was at most only 25%. However, in order to meet the power demand, technology was introduced from the United States, and it shifted to larger sizes such as 125 MW, 12.5 MPa (127 kgf / cm 2 ), 538 / 538 °C reheat type, and then to 250 MW units. Currently, equipment with a supercritical pressure of over 1000 MW (electrostatic precipitator: Figure 7(131)) is adopted. At that time, the environmental problems of thermal power plants were not addressed, and pollutants such as oil removal, flue gas desulfurization, and NOx were discharged as GAS from the collective smoke chambers 101, smoke 111, and 121 of thermal power plants.

[0003] The structure and function of the packed tower scrubber (Figure 3) are as follows: a mist separator (MIST ELIMINATOR) is located at the top of the scrubber (PT), and liquid is sprayed from an external pipe, the scrubbing liquid in (SLi), to the bottom of the mist separator (MIST ELIMINATOR) via a liquid distributor (LIQUID DISTRBUTOR) (Ld). The sprayed liquid is poured into a packed bed (PACKED BED) (PB). Various packings are arranged on the packed bed (PB). For example, possible packing designs include the bell-shaped PA1 in Example 1 (Figure 4A), the cross-partition ring PA2 in Example 2 (Figure 4B), the intalox saddle PA3 in Example 3 (Figure 5A), the metal intalox PA4 in Example 4 (Figure 5B), the Rasching ring PA5 in Example 5 (Figure 6A), and the Sulzer packing PA6 in Example 6 (Figure 6B).

[0004] Liquid is introduced from the gas cleaning liquid input SLi and sprayed from the liquid sprayer Ld. The purified gas cleaning liquid flows downward through the packing of the packet adsorption floor PB. The purified gas cleaning liquid is stored in the liquid reservoir Li. Contaminated air gas is introduced into the liquid reservoir Li from the contaminated air gas input Cg, and the contaminated air gas is cleaned, with clean gas being discharged to the outside at the top of the packed tower. The contaminated air gas and the wastewater from the purified liquid reservoir Li are discharged from the cleaning liquid output SLO and recirculated again, returning to the gas cleaning equipment in the packed tower from the gas cleaning liquid input SLi in the same manner.

[0005] Because the gas-liquid connection in a packed column is continuous, the concentration (or temperature) of the gas and liquid changes continuously. This type of connection is generally called a differential connection and is contrasted with a stepped connection in a stepped column. Packed columns are used for gas suction, distillation, and humidity control through gas-liquid connections, as well as for extraction through liquid-liquid connections. Columns packed with solid packing are also packed columns, but these are often simply called stationary phase columns.

[0006] Regarding fuel, the mid-period energy source shifted from coal to oil during the 1950s. As a result, Japan became dependent on overseas oil, and securing a stable supply of oil is not just a problem for Japan, but a global issue, and one of the most important challenges. Moreover, in recent efforts to increase power generation capacity, measures to combat environmental pollution such as flue gas and dust, including oil desulfurization, flue gas desulfurization, and NOx removal, are research issues surrounding the electric power industry. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Conventional problems include the difficulty of securing petroleum, as well as numerous environmental pollution issues such as oil leakage, flue gas desulfurization, and NOx removal. Furthermore, if the gas velocity is too high, the packed tower will flood, rendering it inoperable. In addition, clogging occurs if the absorbent contains solids, or if sediment is produced due to absorption. Means for solving these problems

[0008] The packed column is set to an apparent gas velocity of 0.3–1.5 m / s (40–70% of the flooding velocity) and a feedwater rate of 15–20 t / m³. 2 • h, liquid gas ratio 1-10 l / m 3 The optimal values ​​are a filling height of 2-5m and a pressure loss of 0.5kPa / tower height m (50mmAp / tower height m). Effect of the invention

[0009] With respect to this invention, if the water supply is optimal, the effect is almost certain to control flooding conditions. It also exhibits relative adaptability to gas volume fluctuations. Furthermore, the pressure loss is not very large. It is easy to manufacture using corrosion-resistant materials. [Brief explanation of the drawing]

[0010] [Figure 1] Thermal power plant [Figure 2] Enlarged view of a thermal power plant [Figure 3] Cross-sectional view of the gas cleaning device for a packed tower. [Figure 4] Examples 1 and 2 of the packing [Figure 5] Examples 3 and 4 of the packing [Figure 6] Examples 5 and 6 of the packing [Figure 7] Enlarged view of a conventional thermal power plant [Modes for carrying out the invention]

[0011] In Figure 1, for thermal power plant 1, when the fuel in the heavy oil tank 100 is burned in the gas collective smoke chamber 10 and the chimneys 11 and 12, smoke is emitted from the gas collective smoke chamber 10 and the smoke outlets 11 and 12. The smoke is sent through pipe P1 to the gas cleaning device PTC in the packed tower.

[0012] Furthermore, before the smoke is discharged into the combined smoke chamber 10, smoke 11, and smoke 12, heavy oil is burned in the fire tower burner 30 in the boiler 23 from the heavy oil tank 100, generating heat in the reheater 22, economizer 21, reheater 24, and superheater 25 in the boiler 23. This heat is used to generate electricity in the turbine generator 27. Once the electricity is generated, high temperatures are produced, and the water in the groundwater intake tank 52 is circulated by the water pump 51 and the main transformer cooling system, which uses the main transformer 29 to cool the heat generated in the thermal burner 30. The heaters 26 and the feedwater pump 31 are operated to provide cooling.

[0013] From here, we will explain using the water storage tank. The water storage tank stores water at the water inlet 55, and the water is stored in the water tank 52 via the water channel 53. From the water tank 52, the water is transported to the turbine generator 27 using the circulating water pump 51.

[0014] After generating electricity in the turbine generator 27, NOx and other pollutants are removed in the flue gas decontamination device 32, and NOx is further removed electrically using a catalyst in the air preheater 20 and electrostatic precipitator 13. After removing as much NOx and other pollutants as possible, the smoke is discharged to the outside through chimneys 10, 11, and 12, and the smoke is carried through pipe P1 to the gas scrubbing device PTC in the packed tower. Thermal power plants are combustion furnaces designed to generate energy and are therefore called stationary energy sources.

[0015] Figure 2 is a magnified view of a thermal power plant. Smoke emitted from the thermal power plant is sent from chimneys 10, 11, and 12 to the lower part of the packed tower gas scrubbing device PTC via pipe P1. Gas scrubbing liquid is stored in the gas scrubbing liquid device SLiE, and pumped up to the top of the gas scrubbing liquid device SLiE by pump P. From there, the gas scrubbing liquid is supplied to the packed tower gas scrubbing device PTC via pipe P2. The gas scrubbing liquid cleaned in the packed tower PT is stored in the gas scrubbing liquid chamber SLOR via pipe P3. Clean gas is discharged to the outside from the top of the packed tower gas scrubbing device PTC.

[0016] Regarding Figure 3, Figure 3 is a cross-sectional view of the packed tower PT. A mist eliminator Me is provided at the upper part of the packed tower. Gas washing liquid is input from the gas washing liquid input SLi, and the gas washing liquid is sprayed downward by the liquid distributor Ld. The sprayed gas washing liquid is distilled in the packet absorption bed PB where the packing is arranged. The purified gas washing liquid falls into the packed tower PT, and the distilled gas washing liquid is stored in the liquid sump Li. The distilled gas washing liquid meets with the contaminated gas from the contaminated air gas input Cg, and the contaminated gas is washed. The washed gas is discharged as clean gas at the upper part of the packed tower PT. The washing liquid output (SCRUBBING LIQUID OUT) SLO stored in the liquid sump Li is discharged to the outside.

[0017] Regarding Figure 4, AB in Figure 4 shows Examples 1 and 2 of the packing. PA1 is a packing called a plastic Berl saddle. PA2 is a packing called a cross partition ring.

[0018] Regarding Figure 5, AB in Figure 5 shows Examples 3 and 4 of the packing. PA3 is a packing called an Intalox saddle. PA4 is a packing called a metal Intalox.

[0019] Regarding Figure 6, AB in Figure 6 shows Examples 5 and 6 of the packing. PA5 is a packing called a plastic Rasching ring. PA6 is a packing called a Sulzer packing.

[0020] Thus, the above-described embodiments are merely illustrative in all respects and should not be construed in a limiting sense. Furthermore, forms and modifications belonging to the equivalent scope of the claims are all within the scope of the present invention.

Industrial Applicability

[0021] The present invention relates to a gas cleaning device for a packed tower in a thermal power plant. When a current nuclear power plant is damaged by natural disasters, it will suffer huge losses due to radioactive contamination. According to the present invention, even when burning coal, charcoal, etc. in a thermal power plant, by means of an optimal control device for the gas cleaning device of the packed tower in the thermal power plant, flooding is prevented, and there is industrial applicability for preventing environmental destruction such as comfortable photochemical smog on the earth.

Description of Signs

[0022] 1 Thermal power plant 10 Kan collective smoke chamber 11, 12 Chimneys 100 Heavy oil tank 23 Boiler 30 Fire tower burner 22 Reheater 21 Coal economizer 24 Reheater 25 Heater 27 Turbine generator 32 Flue gas desulfurization and denitrification device 52 Groundwater storage volume 51 Circulating water pump 29 Main transformer 30 Fire burner 26 Heater 31 Feed water pump 50 Wave dissipating block 55 Water storage port 53 Water storage channel 54 Overflow drainage channel 52 Water storage tank 51 Circulating water pump 32 Flue gas desulfurization and denitrification device 20 Air preheater 13 Electrostatic precipitator PTC Gas cleaning device for packed tower PT Packed tower P1 Pipe P2 Pipe P3 Pipe SLOR gas cleaning liquid chamber P Pump SLiE Cleaning Liquid System Me Mist Separator SLi gas cleaning liquid input Ld liquid sprinkler Li Liquid Reservoir Cg polluting gas input SLO Cleaning Liquid Output PB Packet Adsorption Floor

Claims

1. At a thermal power plant, By flowing water onto the surface of a packing material with a large surface area and bringing the gas into low-speed countercurrent contact, Liquid dispersion type exhaust gas cleaning device

2. In the liquid dispersion type exhaust gas cleaning device according to claim 1, The gas flow velocity is low and the pressure loss is not large. Packed tower gas cleaning system

3. In a component to be built into the packed tower gas cleaning device according to claim 2, It is easy to make using corrosion-resistant materials. packing

4. In the packed tower gas cleaning apparatus of claim 2, Assuming an apparent gas velocity of 0.3 to 1.5 m / s, the water supply rate is 15 to 20 t / min. ２ Let h be the value. packed tower

5. In the packed tower gas cleaning apparatus of claim 2, Liquid-gas ratio 1 to 10¹ / m ３ Assuming a pressure loss of 0.5 kPa / tower height m, packed tower

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