Salt-containing waste gas and waste liquid incinerator system and control method thereof

Abstract

The invention discloses a salt-containing waste gas and waste liquid incinerator system and a control method thereof.The system comprises a vertical incinerator, the vertical incinerator comprises a combustor and an incinerator body which are vertically arranged in sequence from top to bottom, and the combustor is connected with a waste liquid pipeline, a natural gas pipeline and a first waste gas pipeline; a secondary combustion-supporting air annular air bellow, a primary cooling air annular air bellow and a secondary cooling air annular air bellow are sequentially arranged on the furnace body part from top to bottom, and the upper area of the primary cooling air annular air bellow on the furnace body is an incineration area; the area between the upper area of the secondary cooling air annular air bellow on the furnace body and the primary cooling air annular air bellow is a primary cooling area; and the lower area of the secondary cooling air annular bellows on the furnace body is a secondary cooling area. According to the incinerator system, aiming at various waste gases and salt-containing waste liquids, the incineration system can be automatically controlled, molten salt blockage is avoided, nitrogen oxide emission during operation of the whole incineration system can reach 30 mg / Nm < 3 > or below, and energy conservation and environmental protection are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of salt-containing waste gas and waste liquid treatment, and in particular to a salt-containing waste gas and waste liquid incinerator system and a control method thereof. Background Art

[0002] Chemical production is often accompanied by the generation of salt-containing waste gas and waste liquid, such as coal chemical industry and various fine chemicals. At present, the incineration technology of salt-containing waste gas and waste liquid has attracted more and more attention. Compared with other treatment technologies, the incineration technology has a higher waste destruction rate, and the treated flue gas can recover waste heat.

[0003] There are a lot of molten salt droplets in the flue gas of the salt-containing waste gas and waste liquid incinerator. The melting point of salt is usually 800℃~900℃, but this kind of mixed salt still has strong viscosity at 700℃. There are several problems with the salt-containing waste gas and waste liquid incinerators on the market: First, the combustion temperature of the incinerator usually reaches 1100℃. During incineration, the droplets of molten salt in the flue gas are discharged in liquid form at the bottom of the incinerator. Since the incinerator operates under negative pressure, cold air is sucked from the bottom of the furnace, causing the liquid salt to solidify and block the slag discharge port during the slag discharge process. The salt in the furnace accumulates more and more, and finally the liquid level is too high to block the flue gas co-flow space and the furnace is shut down. After the shutdown, the solidified salt is like rock, and workers need to use pneumatic picks or even explosives to remove it. The entire incinerator has a short operation cycle, and the maintenance workload is large and takes a long time; Second, it is difficult to achieve ultra-low emissions of nitrogen oxides in terms of operating emission indicators; Third, when the incinerator load fluctuates, the operation of the incinerator is manually adjusted and controlled, and the degree of automation is low. Summary of the invention

[0004] In view of the above technical problems, the present invention proposes a salt-containing waste gas and waste liquid incinerator system and a control method thereof, which can operate stably for a long time without clogging, can realize automatic control and adjustment, and is an incinerator system with ultra-low nitrogen oxide emissions. The incinerator system is designed with "3 target areas", namely the incineration area, the primary cooling area, and the secondary cooling area, and is equipped with sensors, so that the incinerator can still operate well when the load fluctuates.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical means: A salt-containing waste gas and waste liquid incinerator system comprises a vertical incinerator, wherein the vertical incinerator comprises a furnace body and a burner arranged on the top of the furnace body. The burner is a low-nitrogen burner, and the low-nitrogen burner is connected with: Waste liquid pipeline, natural gas pipeline, first waste gas pipeline and primary combustion air pipeline; The furnace body is provided with a secondary combustion air annular wind box, a primary cooling air annular wind box and a secondary cooling air annular wind box from top to bottom in sequence, wherein: The secondary combustion air annular wind box is connected to a secondary combustion air pipeline; the primary cooling air annular wind box is connected to a primary cooling air pipeline; the secondary cooling air annular wind box is connected to a secondary cooling air pipeline; The upper area of ​​the furnace body located above the primary cooling air annular wind box is the incineration area; The area between the upper part of the secondary cooling air annular wind box and the primary cooling air annular wind box on the furnace body is the primary cooling zone, and a selective non-catalytic reduction reaction ammonia spray gun is installed in the primary cooling zone; The area on the furnace body located below the secondary cooling air annular wind box is the secondary cooling zone; The waste liquid pipeline is provided with a waste liquid regulating valve and a waste liquid flow sensor; The natural gas pipeline is provided with a natural gas regulating valve and a natural gas flow sensor; The first exhaust gas pipeline is provided with a first exhaust gas regulating valve and a first exhaust gas flow sensor; The primary combustion-supporting air duct is provided with a primary combustion-supporting air regulating damper and a primary combustion-supporting air flow sensor; The secondary combustion-supporting air duct is provided with a secondary combustion-supporting air regulating damper; The primary cooling air duct is provided with a primary cooling air regulating damper; The secondary cooling air duct is provided with a secondary cooling air regulating damper.

[0006] Beneficial effects: The incinerator system of the present invention is designed with "3 target areas": incineration area, primary cooling area, and secondary cooling area. The incineration area maintains a temperature of 1100°C to ensure that the waste gas and waste liquid removal rate is greater than 99.99%; the primary cooling area maintains a temperature of 850°C~950°C to ensure reaction efficiency when the denitration reducing agent is sprayed in, and to avoid the burning of the reducing agent ammonia at high temperature to increase the nitrogen oxide content; the secondary cooling area maintains a temperature of 650°C to condense and solidify the molten salt droplets in the flue gas into salt ash to avoid corrosion and blockage of the subsequent system. At the same time, the incinerator system of the present invention adopts ultra-low nitrogen emission technology, uses a low-nitrogen burner, and uses graded air distribution for combustion-supporting air. A selective non-catalytic reduction reaction ammonia spray gun is used to spray the reducing agent in the furnace. A catalytic reduction denitration reactor is also added to the tail gas treatment. The nitrogen oxide emissions of the entire incineration system can reach 30mg / Nm 3 the following.

[0007] In an optional embodiment, a second temperature sensor, an oxygen content sensor and a second pressure sensor are installed on the furnace body of the incineration area; a third temperature sensor is installed on the furnace body of the primary cooling zone; a fourth temperature sensor is installed on the furnace body of the secondary cooling zone; and a first temperature sensor and a first pressure sensor are installed on the primary combustion-supporting air duct.

[0008] Beneficial effect: The present invention monitors the incineration temperature of each target area in real time through temperature sensors, oxygen content sensors and pressure sensors, and cooperates with various regulating valves, flow sensors and regulating dampers to ensure that the incineration area maintains a temperature of 1100°C; the primary cooling area maintains a temperature of 850°C~950°C; and the secondary cooling area maintains a temperature of 650°C.

[0009] In an optional embodiment, a cone area is provided between the burner and the furnace body, and a second exhaust gas nozzle is connected to the cone area.

[0010] Beneficial effect: The second exhaust gas spray gun of the incinerator system of the present invention is suitable for various disordered exhaust gases with low calorific value. The second exhaust gas spray gun is close to the burner, and the exhaust gas is sprayed into the area with the highest heat load in the furnace cross section. The combustion intensity in this area is high. When the flow rate of the disordered exhaust gas changes from 0 to 110%, the furnace combustion is stable.

[0011] In an optional embodiment, it also includes: Waste heat boiler, economizer, bag filter, catalytic reduction denitrification reactor, air preheater, variable frequency induced draft fan and chimney, among which: The flue gas of the vertical incinerator recovers waste heat through the waste heat boiler and the economizer, then passes through the bag filter to remove salt ash in the flue gas, enters the catalytic reduction denitration reactor to remove nitrogen oxides, and then enters the air preheater; the air preheater is provided with an air inlet, an air outlet, a flue gas inlet, and a flue gas outlet, wherein the flue gas inlet is connected to the air outlet of the catalytic reduction denitration reactor, the air inlet is connected to the variable frequency combustion-supporting fan, the preheated air is divided into primary combustion-supporting air entering the primary combustion-supporting air duct, and secondary combustion-supporting air entering the secondary combustion-supporting air duct through the air outlet; the flue gas outlet is discharged through the chimney after passing through the pipeline and the variable frequency induced draft fan.

[0012] Beneficial effect: The flue gas from the incinerator of the present invention is cooled to 230°C after the waste heat is recovered by the waste heat boiler and the economizer, and then passes through a bag filter to remove salt ash in the flue gas, enters a catalytic reduction denitrification reactor to remove nitrogen oxides, and then enters an air preheater to further cool down while preheating the air, and then is discharged from the chimney through an induced draft fan.

[0013] In an optional embodiment, a steam regulating valve and a steam flow sensor are installed on the steam outlet pipeline of the waste heat boiler; a third pressure sensor and a boiler drum liquid level sensor are installed on the steam drum of the waste heat boiler; A boiler feed water regulating valve and a boiler feed water flow sensor are installed on the boiler feed water inlet pipeline of the economizer; The end of the ammonia water supply main pipe is divided into two branches, wherein the first branch pipe is connected to the catalytic reduction denitration reactor after being evaporated into ammonia gas by the ammonia evaporator, and the second branch pipe is connected to the selective non-catalytic reduction reaction ammonia water spray gun after being diluted by the dilution mixer; a denitration reducing agent ammonia water regulating valve is installed on the ammonia water supply main pipe; A nitrogen oxide concentration sensor is installed on the outlet flue of the catalytic reduction denitration reactor; a fourth pressure sensor, mounted on the outlet air duct of the variable frequency combustion-supporting fan; The fifth pressure sensor is installed on the variable frequency cooling fan outlet air duct at one end of the secondary cooling air pipeline.

[0014] The present invention further discloses an incineration method of the salt-containing waste gas and waste liquid incinerator system, wherein the salt-containing waste liquid and the first waste gas enter the burner as fuel to support the main flame; natural gas enters the burner as an auxiliary fuel; By introducing the first combustion-supporting air into the burner and the second combustion-supporting air into the combustion area of ​​the furnace body through the secondary combustion-supporting air annular wind box, the temperature in the combustion area of ​​the furnace body is maintained at not less than 1100°C, ensuring that the waste gas and waste liquid removal rate is greater than 99.99%; The primary cooling air is introduced into the primary cooling area in the furnace body through the primary cooling air annular wind box to maintain the temperature of the primary cooling area of ​​the furnace body at 850℃~950℃; this temperature can ensure the reaction efficiency of the denitrification reducing agent sprayed from the selective non-catalytic reduction reaction ammonia water spray gun, and avoid the burning of the reducing agent ammonia at high temperature to increase the nitrogen oxide content; Secondary cooling air is introduced into the secondary cooling area in the furnace body through the secondary cooling air annular bellows to maintain the temperature of the secondary cooling area in the furnace body no higher than 650°C; the molten salt droplets in the flue gas are condensed and solidified into salt ash to avoid corrosion and blockage of the subsequent system.

[0015] The present invention further discloses a control method for the salt-containing waste gas and waste liquid incinerator system, wherein the primary combustion-supporting air flow sensor is input by the controller for temperature and pressure compensation calculation, and the temperature and pressure compensation data comes from the first temperature sensor and the first pressure sensor; The waste liquid flow sensor manually inputs the required flow rate, and the waste liquid regulating valve opening and the waste liquid flow sensor are designed for single-loop control; The natural gas flow sensor and the second temperature sensor are designed with split-range PID control, and the natural gas regulating valve opening and the natural gas flow sensor are designed with single-loop control; The first exhaust gas flow sensor manually inputs the required flow rate, and the opening of the first exhaust gas regulating valve and the waste liquid flow sensor are designed for single-loop control; The theoretical combustion temperature of the waste gas and waste liquid entering the incinerator after primary combustion air combustion is no less than 1300℃; The primary cooling air regulating damper and the third temperature sensor are controlled by PID; The secondary cooling air regulating damper and the fourth temperature sensor are controlled by PID; The frequency of the variable frequency induced draft fan and the second pressure sensor are controlled by PID; The frequency of the variable frequency combustion-supporting fan and the fourth pressure sensor are controlled by PID; The frequency of the variable frequency cooling fan and the fifth pressure sensor are controlled by PID; The steam regulating valve opening and the third pressure sensor are controlled by PID; The boiler feed water regulating valve opening and the boiler feed water flow sensor are controlled through a single loop; The flow rate of the boiler feed water flow rate sensor is controlled by a three-impulse controller, and the input end of the three-impulse controller is connected to the boiler drum liquid level sensor and the steam flow rate sensor; The opening of the denitrification reducing agent ammonia water regulating valve and the nitrogen oxide concentration sensor are controlled by PID.

[0016] Beneficial effects: The primary combustion-supporting air volume, secondary combustion-supporting air volume, primary cooling air volume, secondary cooling air volume, boiler feed water, steam flow, variable frequency combustion-supporting fan, variable frequency induced draft fan, and variable frequency cooling fan of the present invention are all automatically controlled. A number of single-loop control systems and multi-loop control systems are designed to realize the automation of the incinerator system, with fast adjustment speed, avoidance of manual errors, and conducive to continuous and stable operation of the device.

[0017] In addition, the frequency of the variable frequency induced draft fan and the second pressure sensor are designed for PID control, which can effectively ensure a continuous and stable negative pressure in the furnace, usually maintained at -100Pa. This not only prevents high-temperature toxic exhaust gas from leaking, but is also relatively economical. When the furnace load changes and the flue gas volume changes, this control can avoid excessive fluctuations in furnace pressure caused by traditional fixed-frequency fans.

[0018] The frequency of the variable frequency combustion-supporting fan and the fourth pressure sensor are designed for PID control. When the primary combustion-supporting air and the secondary combustion-supporting air are adjusted separately and cause the combustion-supporting air network to fluctuate, the network pressure can be guaranteed in time to prevent the combustion-supporting air flow from not keeping up and causing incomplete combustion of the incinerator, or even the network pressure is too low and triggers the interlock protection shutdown.

[0019] In an optional embodiment, the flow rate Q4 input by the controller to the primary combustion air flow sensor is obtained by the following formula: Q4=Q1K1+Q2K2+Q3K3, where Q1 is the waste liquid flow, Q2 is the natural gas flow, Q3 is the first waste gas flow, K1 is the first air-fuel ratio, K2 is the second air-fuel ratio, and K3 is the third air-fuel ratio.

[0020] Beneficial effect: The control of the primary combustion air is based on the sum of the air-fuel ratios of the high calorific value gas and liquid, avoiding manual adjustment when the waste gas and waste liquid flow fluctuates, resulting in insufficient combustion air volume and incomplete combustion due to low oxygen content in the flue gas, or excessive combustion air volume and incineration temperature lower than the design value, resulting in incomplete combustion.

[0021] In an optional embodiment, the opening of the secondary combustion air regulating damper is PID controlled with the cascade controller. The main regulator in the cascade controller is used to ensure that the dry basis oxygen content measured by the oxygen content sensor is greater than 6% of the required opening. The sub-regulator in the cascade controller is used to ensure that the temperature measured by the second temperature sensor in the furnace is greater than 1100°C of the required opening. At the same time, the temperature range controller participates in the control. When the main regulator of the cascade controller meets the control conditions but the temperature is less than 1100°C, the temperature range controller controls the natural gas flow sensor to increase the flow rate to help increase the furnace temperature.

[0022] Beneficial effects: The opening of the secondary combustion-supporting air regulating damper of the present invention adopts cascade control, with the flue gas oxygen content as the main regulator, ensuring sufficient oxygen supply to the incineration environment to prevent incomplete combustion; at the same time, a temperature range controller is adopted to timely adjust the natural gas flow to assist combustion, ensuring that the furnace temperature is always maintained at the design value to prevent incomplete combustion.

[0023] In an optional embodiment, the calorific value of the salt-containing waste liquid and the first waste gas is greater than 20 MJ / kg; the second waste gas is various disordered waste gases with a calorific value less than 0.8 MJ / kg, which enter the second waste gas nozzle on the incinerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of a salt-containing waste gas and waste liquid incinerator of the present invention; Among them, 1 is a burner; 2 is a second exhaust gas nozzle; 3 is a secondary combustion air annular wind box; 4 is a vertical incinerator; 5 is a primary cooling air annular wind box; 6 is a secondary cooling air annular wind box; 7 is a selective non-catalytic reduction reaction ammonia spray gun; Figure 2 It is a structural schematic diagram of a salt-containing waste gas and waste liquid incinerator system of the present invention; Among them, 8 is a waste heat boiler; 9 is an economizer; 10 is a bag filter; 11 is a catalytic reduction denitrification reactor; 12 is an air preheater; 13 is a variable frequency induced draft fan; 14 is a variable frequency combustion-supporting fan; 15 is a chimney; 16 is a variable frequency cooling fan; 17 is a waste liquid regulating valve; 18 is a natural gas regulating valve; 19 is a first waste gas regulating valve; 20 is a primary combustion-supporting air regulating damper; 21 is a secondary combustion-supporting air regulating damper; 22 is a primary cooling air regulating damper; 23 is a secondary cooling air regulating damper; 24 is a steam regulating valve; 25 is a boiler feed water regulating valve; 26 is a waste liquid flow sensor; 27 is a natural gas flow sensor Sensor; 28 is the first exhaust gas flow sensor; 29 is the primary combustion air flow sensor; 30 is the first temperature sensor; 31 is the first pressure sensor; 32 is the second temperature sensor; 33 is the oxygen content sensor; 34 is the second pressure sensor; 35 is the third temperature sensor; 36 is the fourth temperature sensor; 37 is the third pressure sensor; 38 is the boiler drum level sensor; 39 is the steam flow sensor; 40 is the boiler feed water flow sensor; 41 is the nitrogen oxide concentration sensor; 42 is the fourth pressure sensor; 43 is the fifth pressure sensor; 44 is the denitrification reducing agent ammonia regulating valve. DETAILED DESCRIPTION

[0025] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0026] like Figure 1 and Figure 2 As shown, a salt-containing waste gas and waste liquid incinerator system includes a vertical incinerator 4, wherein the vertical incinerator 4 includes a furnace body and a burner arranged on the top of the furnace body, and the burner is provided with a waste liquid pipeline interface, a natural gas pipeline interface, a first waste gas pipeline interface and a primary combustion air pipeline interface; The furnace body is provided with a secondary combustion air annular wind box 3, a primary cooling air annular wind box 5 and a secondary cooling air annular wind box 6 in sequence from top to bottom. The secondary combustion air annular wind box 3 is provided with a secondary combustion air pipeline interface; the primary cooling air annular wind box 5 is provided with a primary cooling air pipeline interface; the secondary cooling air annular wind box 6 is provided with a secondary cooling air pipeline interface; The upper area of ​​the furnace body located above the primary cooling air annular wind box 5 is the incineration area, and the furnace body in this area is equipped with a second temperature sensor 32, an oxygen content sensor 33 and a second pressure sensor 34; The area between the upper area of ​​the secondary cooling air annular wind box 6 and the primary cooling air annular wind box 5 on the furnace body is the primary cooling zone, and a third temperature sensor 35 is installed on the furnace body in this area; The area below the secondary cooling air annular wind box 6 on the furnace body is the secondary cooling area, and a fourth temperature sensor 36 is installed on the furnace body in this area; The primary cooling air passes through the primary cooling air annular wind box 5 to enter the furnace to cool the flue gas, and the secondary cooling air passes through the secondary cooling air annular wind box 6 to enter the furnace to cool the flue gas; A first temperature sensor 30 and a first pressure sensor 31 are installed on the primary combustion-supporting air pipeline to the primary combustion-supporting air pipeline interface; The waste liquid pipeline interface is connected to a waste liquid pipeline, and a waste liquid regulating valve and a waste liquid flow sensor are arranged on the waste liquid pipeline; The natural gas pipeline interface is connected to a natural gas pipeline, and a natural gas regulating valve and a natural gas flow sensor are provided on the natural gas pipeline; The first exhaust gas pipeline interface is connected to a first exhaust gas pipeline, and a first exhaust gas regulating valve and a first exhaust gas flow sensor are arranged on the first exhaust gas pipeline; The primary combustion-supporting air pipeline interface is connected to a primary combustion-supporting air pipeline, and the primary combustion-supporting air pipeline is provided with a primary combustion-supporting air regulating damper and a primary combustion-supporting air flow sensor; The secondary cooling air pipeline interface is connected to a secondary combustion air pipeline, and the secondary combustion air pipeline is provided with a secondary combustion air regulating damper; The primary cooling air pipeline interface is connected to a primary cooling air pipeline, and a primary cooling air regulating damper is provided on the primary cooling air pipeline; The secondary cooling air pipeline interface is connected to a secondary cooling air pipeline, and a secondary cooling air regulating damper is arranged on the secondary cooling air pipeline.

[0027] It can be understood that the incinerator system of the present invention is designed with "3 target areas": incineration area, primary cooling area, and secondary cooling area. The incineration area maintains a temperature of 1100°C to ensure that the waste gas and waste liquid removal rate is greater than 99.99%; the primary cooling area maintains a temperature of 850°C to 950°C to ensure the reaction efficiency when the denitrification reducing agent is sprayed in, and to avoid the burning of the reducing agent ammonia at high temperature to increase the nitrogen oxide content; the secondary cooling area maintains a temperature of 650°C to condense and solidify the molten salt droplets in the flue gas into salt ash to avoid corrosion and blockage of the subsequent system.

[0028] In an optional embodiment, taking into account various disordered exhaust gases with low calorific values, a cone area is provided between the burner and the furnace body, and the second exhaust gas nozzle 2 is connected to the cone area.

[0029] It can be understood that the second exhaust gas spray gun of the incinerator system of the present invention is suitable for various disordered exhaust gases with low calorific value. The second exhaust gas spray gun is close to the burner, and the exhaust gas is sprayed into the area with the highest heat load in the furnace cross-section. The combustion intensity in this area is high. When the flow rate of the disordered exhaust gas changes from 0 to 110%, the furnace combustion is stable.

[0030] In an optional embodiment, the burner is a low-nitrogen burner 1; and a selective non-catalytic reduction reaction ammonia water spray gun 7 is installed in the primary cooling zone inside the furnace body.

[0031] The incinerator system of the present invention adopts ultra-low nitrogen emission technology, uses a low-nitrogen burner, uses graded air distribution for combustion-supporting air, uses a selective non-catalytic reduction ammonia spray gun to spray the reducing agent in the furnace, and adds a catalytic reduction denitrification reactor for tail gas treatment. The nitrogen oxide emission of the entire incineration system can reach 30mg / Nm 3 the following.

[0032] In an optional embodiment, it also includes: Waste heat boiler 8, economizer 9, bag filter 10, catalytic reduction denitration reactor 11, air preheater 12, variable frequency induced draft fan 13 and chimney 15, wherein: The flue gas of the vertical incinerator 4 passes through the waste heat boiler 8 and the economizer 9 for waste heat recovery, then passes through the bag filter 10 to remove salt ash in the flue gas, enters the catalytic reduction denitration reactor 11 to remove nitrogen oxides, and then enters the air preheater 12; the air preheater is provided with a first air inlet, a second air inlet, a first air outlet and a second air outlet, wherein the first air inlet is connected to the air outlet of the catalytic reduction denitration reactor 11, and the second air inlet is connected to the variable frequency combustion-supporting fan 14, and the preheated air is divided into primary combustion-supporting air entering the primary combustion-supporting air duct and secondary combustion-supporting air entering the secondary combustion-supporting air duct through the first air outlet; the second air outlet is discharged through the chimney 15 after passing through the pipeline and the variable frequency induced draft fan 13.

[0033] The flue gas of the incinerator of the present invention is cooled to 230°C after the waste heat is recovered by the waste heat boiler and the economizer, then passes through a bag filter to remove salt ash in the flue gas, enters a catalytic reduction denitration reactor to remove nitrogen oxides, and then enters an air preheater to further cool down while preheating the air, and then is discharged from the chimney through an induced draft fan.

[0034] In an optional embodiment, a steam regulating valve 24 and a steam flow sensor 39 are installed on the steam outlet pipeline of the waste heat boiler 8; a third pressure sensor 37 and a boiler drum liquid level sensor 38 are installed on the steam drum of the waste heat boiler 8; A boiler feed water regulating valve 25 and a boiler feed water flow sensor 40 are installed on the boiler feed water inlet pipeline of the economizer 9; The end of the ammonia water supply main pipe is divided into two branches, wherein the first branch pipe is connected to the catalytic reduction denitration reactor 11 after being evaporated into ammonia gas by the ammonia evaporator, and the second branch pipe is connected to the selective non-catalytic reduction reaction ammonia water spray gun 7 after being diluted by the dilution mixer; a denitration reducing agent ammonia water regulating valve 44 is installed on the ammonia water supply main pipe; A nitrogen oxide concentration sensor 41 is installed on the outlet flue of the catalytic reduction denitration reactor 11; A fourth pressure sensor 42 is installed on the outlet air duct of the variable frequency combustion-supporting fan 14; The fifth pressure sensor 43 is installed on the outlet air duct of the variable frequency cooling fan 16 at one end of the secondary cooling air pipeline.

[0035] The present invention further discloses an incineration method of the salt-containing waste gas and waste liquid incinerator system, wherein the salt-containing waste liquid and the first waste gas enter the burner 1 as fuel to support the main flame; natural gas enters the burner 1 as an auxiliary fuel; By introducing the first combustion-supporting air into the burner and introducing the second combustion-supporting air into the combustion area of ​​the furnace body through the secondary combustion-supporting air annular wind box 3, the temperature in the combustion area of ​​the furnace body is maintained at not less than 1100°C, ensuring that the waste gas and waste liquid removal rate is greater than 99.99%; The primary cooling air is introduced into the primary cooling area in the furnace body through the primary cooling air annular wind box 5 to maintain the temperature of the primary cooling area of ​​the furnace body at 850°C to 950°C; this temperature can ensure the reaction efficiency of the denitration reducing agent sprayed from the selective non-catalytic reduction reaction ammonia water spray gun 7, and avoid the burning of the reducing agent ammonia at high temperature to increase the nitrogen oxide content; Secondary cooling air is introduced into the secondary cooling area in the furnace body through the secondary cooling air annular bellows 6 to maintain the temperature of the secondary cooling area in the furnace body not higher than 650°C; the molten salt droplets in the flue gas are condensed and solidified into salt ash to avoid corrosion and blockage of the subsequent system.

[0036] The incinerator system of the present invention is designed with "3 target areas": incineration area, primary cooling area, and secondary cooling area. The incineration area maintains a temperature of 1100°C to ensure that the waste gas and waste liquid removal rate is greater than 99.99%; the primary cooling area maintains a temperature of 850°C to 950°C to ensure the reaction efficiency when the denitrification reducing agent is sprayed in, and to avoid the burning of the reducing agent ammonia at high temperature to increase the nitrogen oxide content; the secondary cooling area maintains a temperature of 650°C to condense and solidify the molten salt droplets in the flue gas into salt ash to avoid corrosion and blockage of the subsequent system.

[0037] The present invention further discloses a control method for the salt-containing waste gas and waste liquid incinerator system, wherein the primary combustion air flow sensor 29 is input by the controller for temperature and pressure compensation calculation, and the temperature and pressure compensation data comes from the first temperature sensor 30 and the first pressure sensor 31; The waste liquid flow sensor 26 manually inputs the required flow rate, and the opening of the waste liquid regulating valve 17 and the waste liquid flow sensor 26 are designed for single-loop control; The natural gas flow sensor 27 and the second temperature sensor 32 are designed with split-range PID control, and the opening of the natural gas regulating valve 18 and the natural gas flow sensor 27 are designed with single-loop control; The first exhaust gas flow sensor 28 manually inputs the required input flow, and the opening of the first exhaust gas regulating valve 19 and the waste liquid flow sensor 26 are designed for single-loop control; The theoretical combustion temperature of the waste gas and waste liquid entering the incinerator after primary combustion air combustion is no less than 1300℃; The primary cooling air regulating damper 22 and the third temperature sensor 35 are controlled by PID; The secondary cooling air regulating damper 23 and the fourth temperature sensor 36 are controlled by PID; The frequency of the variable frequency induced draft fan 13 and the second pressure sensor 34 are controlled by PID; The frequency of the variable frequency combustion-supporting fan 14 and the fourth pressure sensor 42 are controlled by PID; The frequency of the variable frequency cooling fan 16 and the fifth pressure sensor 43 are controlled by PID; The opening of the steam regulating valve 24 and the third pressure sensor 37 are controlled by PID; The opening of the boiler feed water regulating valve 25 and the boiler feed water flow sensor 40 are controlled by a single loop; The flow rate of the boiler feed water flow sensor 40 is controlled by a three-impulse controller, and the input end of the three-impulse controller is connected to the boiler drum liquid level sensor 38 and the steam flow sensor 39; The opening degree of the denitration reducing agent ammonia water regulating valve 44 and the nitrogen oxide concentration sensor 41 are controlled by PID.

[0038] The primary combustion-supporting air volume, secondary combustion-supporting air volume, primary cooling air volume, secondary cooling air volume, boiler feed water, steam volume, variable frequency combustion-supporting fan, variable frequency induced draft fan and variable frequency cooling fan of the present invention are all automatically controlled. A plurality of single-loop control systems and multi-loop control systems are designed to realize the automation of the incinerator system, with fast adjustment speed, avoidance of manual errors in operation, and conducive to continuous and stable operation of the device.

[0039] In addition, the frequency of the variable frequency induced draft fan and the second pressure sensor are designed for PID control, which can effectively ensure a continuous and stable negative pressure in the furnace, usually maintained at -100Pa. This not only prevents high-temperature toxic exhaust gas from leaking, but is also relatively economical. When the furnace load changes and the flue gas volume changes, this control can avoid excessive fluctuations in furnace pressure caused by traditional fixed-frequency fans.

[0040] The frequency of the variable frequency combustion-supporting fan and the fourth pressure sensor are designed for PID control. When the primary combustion-supporting air and the secondary combustion-supporting air are adjusted separately and cause the combustion-supporting air network to fluctuate, the network pressure can be guaranteed in time to prevent the combustion-supporting air flow from not keeping up and causing incomplete combustion of the incinerator, or even the network pressure is too low and triggers the interlock protection shutdown.

[0041] In an optional embodiment, the flow rate Q4 input by the controller to the primary combustion air flow sensor 29 is obtained by the following formula: Q4=Q1K1+Q2K2+Q3K3, where Q1 is the waste liquid flow, Q2 is the natural gas flow, Q3 is the first waste gas flow, K1 is the first air-fuel ratio, K2 is the second air-fuel ratio, and K3 is the third air-fuel ratio.

[0042] The control of the primary combustion-supporting air of the present invention is based on the sum of the air-fuel ratios of the high calorific value gas and liquid, so as to avoid incomplete combustion due to insufficient combustion-supporting air volume and too low oxygen content in the flue gas caused by manual adjustment when the waste gas and waste liquid flow fluctuates, or incomplete combustion due to excessive combustion-supporting air volume and the incineration temperature being lower than the design value.

[0043] In an optional embodiment, the opening of the secondary combustion air regulating damper 21 is PID controlled with the cascade controller. The main regulator in the cascade controller is used to ensure that the dry basis oxygen content measured by the oxygen content sensor 33 is greater than the required opening of 6%, and the sub-regulator in the cascade controller is used to ensure that the temperature measured by the second temperature sensor 32 in the furnace is greater than the required opening of 1100°C. At the same time, the temperature range controller participates in the control. When the main regulator of the cascade controller meets the control conditions but the temperature is less than 1100°C, the temperature range controller controls the natural gas flow sensor 27 to increase the flow rate to help increase the furnace temperature.

[0044] The opening of the secondary combustion-supporting air regulating damper of the present invention adopts cascade control, with the flue gas oxygen content as the main regulator, thereby ensuring sufficient oxygen supply to the incineration environment and preventing incomplete combustion. At the same time, a temperature range controller is adopted to timely adjust the natural gas flow rate to support combustion, thereby ensuring that the furnace temperature is always maintained at the design value and preventing incomplete combustion.

[0045] In an optional embodiment, the calorific value of the salt-containing waste liquid and the first waste gas is greater than 20 MJ / kg; the second waste gas is various disordered waste gases with a calorific value less than 0.8 MJ / kg, and enters the second waste gas nozzle 2 on the incinerator.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A salt-containing waste gas and waste liquid incinerator system, comprising a vertical incinerator (4), wherein the vertical incinerator (4) comprises a furnace body and a burner arranged on the top of the furnace body, characterized in that: The burner is a low-nitrogen burner, and the low-nitrogen burner is connected with: Waste liquid pipeline, natural gas pipeline, first waste gas pipeline and primary combustion air pipeline; The furnace body is provided with a secondary combustion air annular wind box (3), a primary cooling air annular wind box (5) and a secondary cooling air annular wind box (6) in sequence from top to bottom, wherein: The secondary combustion air annular wind box (3) is connected to a secondary combustion air pipeline; the primary cooling air annular wind box (5) is connected to a primary cooling air pipeline; the secondary cooling air annular wind box (6) is connected to a secondary cooling air pipeline; The upper area of ​​the furnace body located above the primary cooling air annular wind box (5) is the incineration area; The area on the furnace body between the upper part of the secondary cooling air annular wind box (6) and the primary cooling air annular wind box (5) is a primary cooling zone, and a selective non-catalytic reduction reaction ammonia water spray gun (7) is installed in the primary cooling zone; The area on the furnace body below the secondary cooling air annular wind box (6) is a secondary cooling zone; The waste liquid pipeline is provided with a waste liquid regulating valve (17) and a waste liquid flow sensor (26); The natural gas pipeline is provided with a natural gas regulating valve (18) and a natural gas flow sensor (27); The first exhaust gas pipeline is provided with a first exhaust gas regulating valve (19) and a first exhaust gas flow sensor (28); The primary combustion-supporting air duct is provided with a primary combustion-supporting air regulating damper (20) and a primary combustion-supporting air flow sensor (29); The secondary combustion-supporting air duct is provided with a secondary combustion-supporting air regulating damper (21); The primary cooling air duct is provided with a primary cooling air regulating damper (22); The secondary cooling air duct is provided with a secondary cooling air regulating damper (23).

2. The salt-containing waste gas and waste liquid incinerator system according to claim 1 is characterized in that: A second temperature sensor (32), an oxygen content sensor (33) and a second pressure sensor (34) are installed on the furnace body of the incineration area; A third temperature sensor (35) is installed on the furnace body of the primary cooling zone; A fourth temperature sensor (36) is installed on the furnace body of the secondary cooling zone; A first temperature sensor (30) and a first pressure sensor (31) are installed on the primary combustion-supporting air duct.

3. The salt-containing waste gas and waste liquid incinerator system according to claim 2 is characterized in that: A cone region is provided between the burner and the furnace body, and a second exhaust gas nozzle (2) is connected to the cone region.

4. The salt-containing waste gas and waste liquid incinerator system according to claim 3 is characterized in that: Also includes: A waste heat boiler (8), an economizer (9), a bag filter (10), a catalytic reduction denitration reactor (11), an air preheater (12), a variable frequency induced draft fan (13) and a chimney (15), wherein: The flue gas of the vertical incinerator (4) passes through a waste heat boiler (8) and an economizer (9) for waste heat recovery, then passes through a bag filter (10) to remove salt ash in the flue gas, enters a catalytic reduction denitration reactor (11) to remove nitrogen oxides, and then enters an air preheater (12); the air preheater is provided with an air inlet, an air outlet, a flue gas inlet, and a flue gas outlet, wherein the flue gas inlet is connected to the air outlet of the catalytic reduction denitration reactor (11), the air inlet is connected to a variable frequency combustion-supporting fan (14), and the preheated air is divided into primary combustion-supporting air entering the primary combustion-supporting air pipeline and secondary combustion-supporting air entering the secondary combustion-supporting air pipeline through the air outlet; the flue gas outlet is discharged through a pipeline and a variable frequency induced draft fan (13) and then through the chimney (15).

5. The salt-containing waste gas and waste liquid incinerator system according to claim 4 is characterized in that: A steam regulating valve (24) and a steam flow sensor (39) are installed on the steam outlet pipeline of the waste heat boiler (8); a third pressure sensor (37) and a boiler drum liquid level sensor (38) are installed on the steam drum of the waste heat boiler (8); A boiler feed water regulating valve (25) and a boiler feed water flow sensor (40) are installed on the boiler feed water inlet pipeline of the economizer (9); The end of the ammonia water supply main pipe is divided into two branches, wherein the first branch pipe is connected to the catalytic reduction denitration reactor (11) after being evaporated into ammonia gas by the ammonia evaporator, and the second branch pipe is connected to the selective non-catalytic reduction reaction ammonia water spray gun (7) after being diluted by the dilution mixer; a denitration reducing agent ammonia water regulating valve (44) is installed on the ammonia water supply main pipe; A nitrogen oxide concentration sensor (41) is installed on the outlet flue of the catalytic reduction denitration reactor (11); a fourth pressure sensor (42) mounted on an outlet air duct of the variable frequency combustion-supporting fan (14); A fifth pressure sensor (43) is mounted on an outlet air duct of a variable frequency cooling fan (16) at one end of the secondary cooling air pipeline.

6. The incineration method of the salt-containing waste gas and waste liquid incinerator system according to claim 1 is characterized in that: The salt-containing waste liquid and the first waste gas enter the burner (1) as fuel to support the main flame; the natural gas enters the burner (1) as auxiliary fuel; By introducing the first combustion-supporting air into the burner and introducing the second combustion-supporting air into the combustion area of ​​the furnace body through the secondary combustion-supporting air annular wind box (3), the temperature in the combustion area of ​​the furnace body is maintained at not less than 1100° C., ensuring that the waste gas and waste liquid removal rate is greater than 99.99%; The primary cooling air is introduced into the primary cooling area in the furnace body through the primary cooling air annular wind box (5) to maintain the temperature of the primary cooling area of ​​the furnace body at 850° C. to 950° C.; this temperature can ensure the reaction efficiency of the denitration reducing agent sprayed from the selective non-catalytic reduction reaction ammonia water spray gun (7) and avoid the burning of the reducing agent ammonia at high temperature to increase the nitrogen oxide content; Secondary cooling air is introduced into the secondary cooling area in the furnace body through the secondary cooling air annular bellows (6) to maintain the temperature of the secondary cooling area in the furnace body not higher than 650° C.; the molten salt droplets in the flue gas are condensed and solidified into salt ash, thereby preventing the subsequent system from being corroded and blocked.

7. The control method of the salt-containing waste gas and waste liquid incinerator system according to claim 5 is characterized in that: The primary combustion-supporting air flow sensor (29) is input into the controller for temperature and pressure compensation calculation, and the temperature and pressure compensation data comes from the first temperature sensor (30) and the first pressure sensor (31); The waste liquid flow sensor (26) manually inputs the required input flow rate, and the opening of the waste liquid regulating valve (17) and the waste liquid flow sensor (26) are designed to be controlled in a single loop; The natural gas flow sensor (27) and the second temperature sensor (32) are designed with split-range PID control, and the opening of the natural gas regulating valve (18) and the natural gas flow sensor (27) are designed with single-loop control; The first exhaust gas flow sensor (28) manually inputs the required input flow, and the opening of the first exhaust gas regulating valve (19) and the waste liquid flow sensor (26) are designed for single-loop control; The theoretical combustion temperature of the waste gas and waste liquid entering the incinerator after primary combustion air combustion is no less than 1300℃; The primary cooling air regulating damper (22) and the third temperature sensor (35) are controlled by PID; The secondary cooling air regulating damper (23) and the fourth temperature sensor (36) are controlled by PID; The frequency of the variable frequency induced draft fan (13) and the second pressure sensor (34) are controlled via PID; The frequency of the variable frequency combustion-supporting fan (14) and the fourth pressure sensor (42) are controlled via PID; The frequency of the variable frequency cooling fan (16) and the fifth pressure sensor (43) are controlled by PID; The opening of the steam regulating valve (24) and the third pressure sensor (37) are controlled by PID; The opening of the boiler feed water regulating valve (25) and the boiler feed water flow sensor (40) are controlled via a single loop; The flow rate of the boiler feed water flow rate sensor (40) is controlled by a three-impulse controller, and the input end of the three-impulse controller is connected to the boiler drum liquid level sensor (38) and the steam flow rate sensor (39); The opening of the denitration reducing agent ammonia water regulating valve (44) and the nitrogen oxide concentration sensor (41) are controlled by PID.

8. The control method of the salt-containing waste gas and waste liquid incinerator system according to claim 7 is characterized in that: The flow rate Q4 input by the controller from the primary combustion air flow sensor (29) is obtained by the following formula: Q4=Q1K1+Q2K2+Q3K3, where Q1 is the waste liquid flow rate, Q2 is the natural gas flow rate, Q3 is the first waste gas flow rate, K1 is the first air-fuel ratio, K2 is the second air-fuel ratio, and K3 is the third air-fuel ratio.

9. The control method of the salt-containing waste gas and waste liquid incinerator system according to claim 7, characterized in that: The opening of the secondary combustion air regulating damper (21) is PID-controlled with the cascade controller. The main regulator in the cascade controller is used to ensure that the dry oxygen content measured by the oxygen content sensor (33) is greater than the required opening of 6%. The sub-regulator in the cascade controller is used to ensure that the temperature measured by the second temperature sensor (32) in the furnace is greater than or equal to 1100°C. At the same time, the temperature split-range controller participates in the control. When the main regulator of the cascade controller meets the control conditions but the temperature is less than 1100°C, the temperature split-range controller controls the natural gas flow sensor (27) to increase the flow rate to help increase the furnace temperature.

10. The control method of the salt-containing waste gas and waste liquid incinerator system according to claim 7, characterized in that: The calorific value of salty waste liquid and first waste gas is greater than 20MJ / kg; The second waste gas is various disordered waste gases with a calorific value of less than 0.8 MJ / kg, and enters the second waste gas nozzle (2) on the incinerator.

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