A method of starting a fluidized bed boiler

Abstract

This disclosure relates to a method for starting up a fluidized bed boiler. By spraying an adsorbent into the furnace during the boiler's start-up, NOx and SOx in the flue gas are adsorbed, reducing the emission concentrations of NOx and SOx during the boiler's startup process. This reduces the pressure on subsequent in-furnace desulfurization (CFB) and SNCR and SCR denitrification processes, thereby achieving the goal of ultra-low emissions throughout the entire process of the circulating fluidized bed boiler. This invention is simple to operate, low in cost, and does not cause secondary pollution.

Description

Technical Field

[0001] This disclosure relates to the technical field of pollutant control and suppression methods for ultra-low emission circulating fluidized bed boilers (CFB), and more specifically, to a method for starting up a fluidized bed boiler. Background Technology

[0002] In recent years, people have paid increasing attention to environmental protection, and the national standards for air pollutant emissions from thermal power plants have become increasingly stringent. The pollution caused by burning coal in thermal power plants cannot be ignored. The combustion of coal produces many pollutants that are highly harmful to the environment, such as NOx. x Sulfur oxides and their derivatives, such as SO2, SO3, sulfuric acid mist, and acid rain, not only corrode coal-fired equipment and shorten the service life of coal-fired boilers, but also cause environmental pollution, resulting in irreversible damage to the health of animals, plants, and humans. x The formation mechanisms of NO can be divided into three categories: thermal, rapid, and fuel-based. Among these three types, fuel-based NO... x And it accounts for the vast majority. SO₂ generated during coal combustion... x It may also affect NO x The formation of.

[0003] Currently, most countries in the world widely use dry flue gas denitrification technology, with SNCR being the most common. A commonly used desulfurization technology is the limestone-gypsum wet desulfurization process. The desulfurizing agent is limestone powder (CaCO3), which is prepared into limestone slurry through a limestone slurry tank. Limestone, due to its good chemical activity and low price, has become the most widely used raw material for preparing desulfurizing agents in wet desulfurization processes worldwide. In the absorption tower, SO2 in the flue gas reacts with limestone to produce calcium sulfite, which is then forcibly oxidized in situ to gypsum. The gypsum, after secondary dehydration treatment, can be sold as a byproduct.

[0004] However, during the low-load startup of CFB boilers, the low bed temperature leads to low desulfurization efficiency and high SO2 emission concentration. Furthermore, the startup process requires fuel oil or natural gas to meet start-up conditions, resulting in high NO2 emissions. x Emissions increase, and since the flue gas temperature at the SNCR is not at the removal window, SO2 and NO emissions increase during the start-up of the circulating fluidized bed boiler. x High emission concentrations have become a bottleneck for achieving ultra-low emissions from CFB boilers. Summary of the Invention

[0005] The purpose of this disclosure is to provide a method for starting up a fluidized bed boiler, thereby reducing NO in the flue gas during the start-up process of a circulating fluidized bed boiler. x and SO xThis invention reduces emissions, thereby decreasing the pressure on subsequent CFB in-furnace desulfurization and SNCR and SCR denitrification, thus achieving the goal of ultra-low emissions throughout the entire circulating fluidized bed boiler process. The invention is simple to operate, low in cost, and does not cause secondary pollution.

[0006] To achieve the above objectives, the first aspect of this disclosure provides a method for starting up a fluidized bed boiler, the method comprising: spraying an adsorbent into the furnace during the start-up and ignition of the circulating fluidized bed boiler; wherein the adsorbent is sprayed at the top of the furnace.

[0007] Optionally, the adsorbent comprises a natural colloidal adsorbent; the natural colloidal adsorbent comprises cis-1,4-polyisoprene, biomass activated coke powder, and iron ore powder; the particle size of the biomass activated coke powder and iron ore powder is 10-50 μm.

[0008] Optionally, the softening point of the adsorbent is between 130°C and 180°C; preferably between 150°C and 160°C.

[0009] Optionally, the furnace ignition adopts a fixed bed ignition method, wherein the adsorbent is sprayed in after the bituminous coal is added into the furnace and before the bituminous coal is fully ignited.

[0010] Optionally, the temperature of the fixed bed is 400–700°C when the adsorbent is sprayed in.

[0011] Optionally, the fixed-bed ignition includes the following steps: starting the induced draft fan and the blower, adding igniting bituminous coal into the furnace, spraying in adsorbent adhesive, and measuring the NO content in the flue gas. x and SO x The emission concentration of NO; x The emission concentration is lower than NO x Threshold, and SO x The emission concentration is lower than SO x When the threshold is reached, the spraying of the absorbent adhesive is stopped; wherein, the NO x The threshold is 30–40 mg / m³ 3 The SO x The threshold is 20–30 mg / m³ 3 .

[0012] Optionally, the furnace ignition adopts a pre-combustion chamber fluidized oil ignition method, wherein hot flue gas is used to bring the bottom material to a critical fluidization state, and then the adsorbent is sprayed in.

[0013] Optionally, the furnace temperature is 400–700°C when the absorbent is sprayed in.

[0014] Optionally, the fluidized bed ignition in the pre-combustion chamber includes the following steps: starting the induced draft fan and the blower, igniting the fuel gun, spraying the adsorbent into the furnace, and measuring the NO in the flue gas. xEmission concentration and SO x Emission concentration; when NO x The emission concentration is lower than NO x Threshold, and SO x The emission concentration is lower than SO x Stop spraying the absorbent when the threshold is reached;

[0015] Wherein, the NO x The threshold is 30–40 mg / m³ 3 The SO x The threshold is 20–30 mg / m³ 3 .

[0016] Optionally, the minimum flow rate of the injected adsorbent is calculated using equation (1).

[0017]

[0018] Where M is the flow rate of the injected adsorbent, in g / m³. 3 C represents the nitrogen oxide concentration (mg / m³) when no adsorbent was injected during the start-up ignition process. 3 α is the catalytic reaction coefficient; λ is the temperature reaction coefficient; β is the empirical coefficient.

[0019] The α is (0.4~0.6)×10 -3 The value of λ is any value from -0.006 to -0.01; the value of β is any value from 0.05 to 0.07.

[0020] Through the above technical solution, the method for starting up a fluidized bed boiler provided in this disclosure involves spraying adsorbent polymer into the furnace during the start-up and ignition of the circulating fluidized bed boiler to remove NO from the flue gas. x and SO x Adsorption reduces NO in flue gas during the start-up process of a circulating fluidized bed boiler. x and SO x The emission concentration is reduced, thus decreasing the pressure on subsequent CFB in-furnace desulfurization and SNCR and SCR denitrification, thereby achieving the goal of ultra-low emissions throughout the circulating fluidized bed boiler process. This invention is simple to operate, low in cost, and does not cause secondary pollution. Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0022] Figure 1 This is a diagram showing the adsorbent being sprayed into the furnace in Embodiment 1 of this disclosure;

[0023] Figure 2 The adsorption of NO by the adsorbent in Example 1 of this disclosure x A schematic diagram of SO2.

[0024] Explanation of reference numerals in the attached figures

[0025] 1: Fuel zone; 2: Adsorbent; 3: Flue gas; 4: Separator; 5: Return valve; 6: Upper part of furnace. Detailed Implementation

[0026] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0027] This disclosure provides a method for starting up a fluidized bed boiler, the method comprising: spraying an adsorbent into the boiler during start-up and ignition; wherein the adsorbent is sprayed at the top of the boiler. Spraying the adsorbent at the top of the boiler can adsorb pollutant NO in the generated flue gas. x and SO x .

[0028] This disclosure describes a method for removing NO from flue gas by spraying an adsorbent into the furnace during the start-up and ignition of a circulating fluidized bed boiler. x and SO x Adsorption is performed to reduce NO in the flue gas during the start-up process of a circulating fluidized bed boiler. x and SO x The reduced emissions will alleviate the pressure on subsequent CFB in-furnace desulfurization and SNCR and SCR denitrification, thereby achieving the goal of ultra-low emissions throughout the entire circulating fluidized bed boiler process.

[0029] According to one embodiment of this disclosure, the adsorbent comprises a natural colloidal adsorbent; the natural colloidal adsorbent comprises cis-1,4-polyisoprene, biomass activated coke powder, and iron ore powder; the particle size of the biomass activated coke powder and iron ore powder is 10–50 μm, preferably 20–40 μm. In the above embodiment, by selecting the above-mentioned natural colloidal adsorbent, NO in flue gas can be effectively adsorbed. x and SO x It achieves excellent adsorption.

[0030] According to one embodiment of this disclosure, the softening point of the adsorbent is between 130°C and 180°C; preferably between 150°C and 160°C. In the above embodiment, the adsorbent softens at 150°C to 160°C after entering the furnace, allowing for better adsorption of NO in the flue gas. x and SO x .

[0031] According to one embodiment of this disclosure, the furnace ignition adopts a fixed-bed ignition method, wherein the adsorbent is sprayed after the bituminous coal is added to the furnace but before the bituminous coal is fully ignited. In the above embodiment, the adsorbent is sprayed at this time point, so the adsorbent will not soften and stick to the heated surface wall.

[0032] According to one embodiment of this disclosure, the bed temperature of the fixed bed is 400–700°C, preferably 450–650°C, when the adsorbent is sprayed in. In the above embodiment, spraying the adsorbent at the preferred bed temperature allows for better adsorption of NO in the flue gas. x and SO x .

[0033] According to one embodiment of this disclosure, the fixed bed ignition includes the following steps: A base material with a particle size of 0-3 mm, preferably 0-1 mm, is laid on the bed. The base material contains 0-0.5 wt% carbon, preferably less than 0.2 wt%. Firewood is placed on the base material and ignited. Lump coal is added, with a particle size of 0-50 mm, preferably 10-30 mm. The thickness of the firewood and lump coal is 150-200 mm, preferably 160-180 mm. The base material is one or more of coal slag, coal ash, and quartz sand. Unburnt large lumps of coal are hooked out with a fire hook, and the charcoal fire on the bed surface is leveled.

[0034] Start the induced draft fan and blower to achieve a micro-fluidized state in the feed bed. Add igniting bituminous coal into the furnace. This process utilizes the red embers formed by the combustion at the top to gradually heat the entire feed bed and ignite the bituminous coal. Spray adsorbent adhesive onto the furnace top to adsorb NO emitted from the flue gas. x and SO x and measure NO in flue gas x and SO x The emission concentration of NO; x The emission concentration is lower than NO x Threshold, and SO x The emission concentration is lower than SO x When the threshold is reached, the spraying of the absorbent adhesive is stopped; wherein, the NO x The threshold is 30–40 mg / m³ 3 Preferably 34–36 mg / m³ 3 The SO x The threshold is 20–30 mg / m³ 3 The preferred concentration is 24–26 mg / m³. 3 In the above embodiments, fixed-bed ignition through the above steps can better adsorb NO in the flue gas. x and SO x .

[0035] According to one embodiment of this disclosure, the furnace ignition adopts a pre-combustion chamber fluidized oil ignition method, wherein hot flue gas is used to bring the bottom material to a critical fluidized state, and then the adsorbent is sprayed in. The basic principle of pre-combustion chamber fluidized oil ignition is that the fuel atomized and completely combusts in the pre-combustion chamber, and the resulting high-temperature flue gas and flame (1500°C) are uniformly mixed with the cold air supplied by the blower to form hot flue gas at about 850°C, which enters the bed through the air chamber and air cap to heat the bed material. In the above embodiment, the pre-combustion chamber fluidized oil ignition method does not result in low-temperature or high-temperature coking.

[0036] According to one embodiment of this disclosure, the furnace temperature is 400–700°C, preferably 400–650°C, when the adsorbent is sprayed in. In the above embodiment, spraying the adsorbent at the preferred bed temperature allows for better adsorption of NO in the flue gas. x and SO x .

[0037] According to one embodiment of this disclosure, the fluidized oil ignition in the pre-combustion chamber includes the following steps: laying a substrate with a particle size of 0-3 mm, preferably 0-1 mm, on the bed; starting the air compressor and oil pump; then starting the induced draft fan and blower; igniting the oil gun; opening the air supply damper; and adjusting the air supply volume to bring the substrate to a critical fluidized state; and spraying an adsorbent into the furnace to adsorb NO emitted from the flue gas. x and SO x and measure NO in flue gas x Emission concentration and SO x Emission concentration; when NO x The emission concentration is lower than NO x Threshold, and SO x The emission concentration is lower than SO x Stop spraying the absorbent when the threshold is reached;

[0038] Wherein, the NO x The threshold is 30–40 mg / m³ 3 Preferably 34–36 mg / m³ 3 The SO x The threshold is 20–30 mg / m³ 3 The preferred concentration is 24–26 mg / m³. 3 In the above embodiments, the fluidized bed ignition in the pre-combustion chamber, performed through the above steps, can better adsorb NO in the flue gas. x and SO x .

[0039] According to one embodiment of this disclosure, the minimum flow rate of the injected adsorbent is calculated using equation (1).

[0040]

[0041] Where M is the flow rate of the injected adsorbent, in g / m³. 3 C represents the nitrogen oxide concentration (mg / m³) when no adsorbent was injected during the start-up ignition process. 3 α is the catalytic reaction coefficient; λ is the temperature reaction coefficient; β is the empirical coefficient; and α is (0.4~0.6)×10⁻⁶. -3 The λ value is any value from -0.006 to -0.01; the β value is any value from 0.05 to 0.07. The above implementation method is beneficial for controlling NO in flue gas. x and SO x It achieves excellent adsorption. In this disclosure, the minimum value can be understood as the value required to achieve NO. x and SO x The minimum amount of adsorbent required to be sprayed in accordance with emission requirements.

[0042] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0043] The raw materials for the adsorbent gel used in the following examples were purchased from Shanghai Guchen Biotechnology Co., Ltd. The raw materials included cis-1,4-polyisoprene, biomass activated coke powder, and iron ore powder. The raw materials were processed into the adsorbent gel through crushing, adding a small amount of water and stirring, drying, and final crushing. x and SO x The emission concentration was measured using a flue gas analyzer.

[0044] The circulating fluidized bed boiler used in this disclosure has a capacity of 1065 t / h, a load of 30%, and a flue gas volume of 318,500 m³. 3 / h.

[0045] Example 1

[0046] Ignition of the fixed bed: Spread 1mm diameter coal ash on the bed with a carbon content of 0.1%, put firewood on the bottom material and ignite it, add 30mm diameter coal lumps, and the thickness of the firewood and coal lumps should be 170mm; use a fire hook to remove the unburned large coal lumps and level the charcoal fire on the bed surface.

[0047] Start the induced draft fan and blower, such as Figure 1 As shown, bituminous coal was added to the fuel zone inside the furnace. Before the coal was fully ignited, adsorbent was sprayed onto the furnace top at a temperature of 400°C. After entering the furnace, the adsorbent softened at 160°C. The NO content in the flue gas was then measured. x and SO x The emission concentration of NO x Emission concentration below 35 mg / m³ 3 SO x Emission concentration below 25 mg / m³ 3Then stop spraying the absorbent adhesive.

[0048] The adsorbent comprises cis-1,4-polyisoprene, biomass activated coke powder, and iron ore powder, wherein the particle size of the biomass activated coke powder and iron ore powder is 30 μm.

[0049] In this Example 1, C represents the nitrogen oxide concentration when no adsorbent gel is sprayed under the fixed-bed ignition method, i.e., 189 mg / m³. 3 Given α = 0.00048, λ = -0.0094, and β = 0.07, the calculated flow rate of the injected adsorbent is 0.2 g / m³. 3 .

[0050] Example 2

[0051] Fixed bed ignition: The method for starting the fluidized bed boiler in this embodiment is the same as in Embodiment 1, except that the flow rate of the injected adsorbent is 0.3 g / m³. 3 .

[0052] Example 3

[0053] Fixed bed ignition: The method for starting the fluidized bed boiler in this embodiment is the same as in Embodiment 1, except that the flow rate of the injected adsorbent is 0.15 g / m³. 3 .

[0054] Example 4

[0055] Pre-combustion chamber fluidized oil ignition: Lay a 1mm particle size base material on the bed, start the air compressor and oil pump, then start the induced draft fan and blower, ignite the oil gun, open the air supply damper, and adjust the air supply volume to bring the base material to the critical fluidization state.

[0056] When the furnace temperature is 400℃, adsorbent is sprayed onto the furnace top. After entering the furnace, the adsorbent softens at 160℃. The NO content in the flue gas is then measured. x and SO x The emission concentration of NO x Emission concentration below 35 mg / m³ 3 SO x Emission concentration below 25 mg / m³ 3 Then stop spraying the absorbent adhesive.

[0057] The adsorbent comprises cis-1,4-polyisoprene, biomass activated coke powder, and iron ore powder, wherein the particle size of the biomass activated coke powder and iron ore powder is 30 μm. In Example 4, C is the nitrogen oxide concentration when no adsorbent is injected under the fluidized bed ignition method in the pre-combustion chamber, i.e., 192 mg / m³. 3 Given α = 0.00048, λ = -0.0094, and β = 0.07, the calculated flow rate of the injected adsorbent is 0.2 g / m³. 3 .

[0058] Example 5

[0059] Fluidized oil ignition in the pre-combustion chamber: The method for starting the fluidized bed boiler in this embodiment is the same as in embodiment 4, except that the flow rate of the injected adsorbent is 0.3 g / m³. 3 .

[0060] Example 6

[0061] Fluidized oil ignition in the pre-combustion chamber: The method for starting the fluidized bed boiler in this embodiment is the same as in embodiment 4, except that the flow rate of the injected adsorbent is 0.15 g / m³. 3 .

[0062] Comparative Example 1

[0063] Fixed bed ignition: The method for starting the fluidized bed boiler in this comparative example is the same as in Example 1, except that no adsorbent is sprayed in.

[0064] Comparative Example 2

[0065] Fixed bed ignition: The method for starting the fluidized bed boiler in this comparative example is the same as in Example 1, except that an adsorbent is sprayed into the upper part of the furnace.

[0066] Comparative Example 3

[0067] Pre-combustion chamber fluidized oil ignition: The method for starting up the fluidized bed boiler in this comparative example is the same as in Example 4, except that: no adsorbent is sprayed in.

[0068] Comparative Example 4

[0069] Pre-combustion chamber fluidized oil ignition: The method for starting the fluidized bed boiler in this comparative example is the same as in Example 4, except that an adsorbent is sprayed into the upper part of the furnace.

[0070] Table 1

[0071] <![CDATA[NO x Emission concentration (mg / m³) 3 )]]> <![CDATA[SO x Emission concentration (mg / m³) 3 )]]> Example 1 40 30 Example 2 38 28 Example 3 67 79 Comparative Example 1 189 528 Comparative Example 2 135 464

[0072] Table 1 shows the NO levels under fixed-bed ignition methods. x and SO x As shown in Table 1, compared with Comparative Examples 1-2, the NO emission concentration using the ignition methods of Examples 1-3 of this disclosure is significantly lower. x and SO x The emission concentration is low. Specifically, compared to Example 3, in Example 1, when the flow rate of the injected adsorbent is lower than the calculated minimum value, NO... x and SO x Increased emission concentrations of NO, and the adsorption of NO by the adsorbent. x and SO x The adsorption effect was poor; compared with Example 1, Comparative Example 1 did not spray natural glue, and therefore could not adsorb NO during gas furnace ignition.x and SO x Adsorption occurs, therefore NO x and SO x The emission concentration was high; compared with Example 1, in Comparative Example 2, the adsorbent was not sprayed into the furnace top, therefore the adsorbent had a lower concentration of NO. x and SO x The adsorption effect of NO is poor. x and SO x High emission concentration.

[0073] Table 2

[0074]

[0075]

[0076] Table 2 shows the NO levels under the pre-combustion chamber fluidized carburetor ignition method. x and SO x As shown in Table 2, compared with Comparative Examples 3-4, the emission concentration of NO in the flue gas obtained by using the ignition methods of Examples 4-6 of this disclosure is significantly lower. x and SO x The emission concentration was low. In Example 4, compared to Example 6, when the flow rate of the injected adsorbent was lower than the calculated minimum, the NO concentration in the flue gas was lower. x and SO x Increased emission concentrations of NO, and the adsorption of NO by the adsorbent. x and SO x The adsorption effect was poor; compared with Example 4, Comparative Example 3 did not spray natural glue, and therefore could not adsorb NO in the flue gas during start-up and ignition. x and SO x Adsorption occurs, therefore NO x and SO x The emission concentration was relatively high; compared with Example 4, in Comparative Example 4, the adsorbent was not sprayed into the furnace top, therefore the adsorbent had a higher concentration of NO in the flue gas. x and SO x The adsorption effect of NO is poor. x and SO x High emission concentration.

[0077] In summary, the method for starting up a fluidized bed boiler provided by this invention reduces NO emissions. x and SO x The emission concentration is reduced to decrease the pressure on subsequent CFB in-furnace desulfurization and SNCR and SCR denitrification, thereby achieving the goal of ultra-low emissions throughout the entire process of the circulating fluidized bed boiler.

[0078] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0079] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0080] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for starting up a fluidized bed boiler, characterized in that, The method includes: spraying an adsorbent into the furnace during the start-up and ignition of a circulating fluidized bed boiler; the adsorbent is sprayed at the top of the furnace. The adsorbent includes a natural colloidal adsorbent; The natural colloidal adsorbent comprises cis-1,4-polyisoprene, biomass activated coke powder, and iron ore powder; the particle size of the biomass activated coke powder and iron ore powder is 10~50μm; The softening point of the adsorbent is between 130℃ and 180℃; after entering the furnace, the adsorbent softens at 150℃ to 160℃, allowing for better adsorption of NO in the flue gas. x and SO x .

2. The method according to claim 1, wherein, The furnace ignition adopts a fixed bed ignition method, wherein the adsorbent is sprayed in after the bituminous coal is added into the furnace and before the bituminous coal is fully ignited.

3. The method according to claim 2, wherein, The temperature of the fixed bed is 400~700℃ when the adsorbent is sprayed in.

4. The method according to claim 2, wherein, The fixed-bed ignition includes the following steps: starting the induced draft fan and the blower, adding igniting bituminous coal into the furnace, spraying in adsorbent gel, and measuring the NO content in the flue gas. x and SO x The emission concentration of NO; x The emission concentration is lower than NO x Threshold, and SO x The emission concentration is lower than SO x Stop spraying the absorbent when the threshold is reached; Wherein, the NO x The threshold is 30~40 mg / m³ 3 The SO x The threshold is 20~30 mg / m³ 3 .

5. The method according to claim 1, wherein, The furnace ignition adopts a pre-combustion chamber fluidized oil ignition method, in which hot flue gas is used to bring the bottom material to a critical fluidization state, and then the adsorbent is sprayed in.

6. The method according to claim 5, wherein, When the adsorbent is sprayed in, the temperature inside the furnace is 400~700℃.

7. The method according to claim 5, wherein, The fluidized bed ignition in the pre-combustion chamber includes the following steps: starting the induced draft fan and the blower, igniting the fuel gun, spraying the adsorbent into the furnace, and measuring the NO in the flue gas. x Emission concentration and SO x Emission concentration; when NO x The emission concentration is lower than NO x Threshold, and SO x The emission concentration is lower than SO x Stop spraying the absorbent when the threshold is reached; Wherein, the NO x The threshold is 30~40 mg / m³ 3 The SO x The threshold is 20~30 mg / m³ 3 .

8. The method according to any one of claims 1 to 7, characterized in that, The minimum flow rate of the injected adsorbent is calculated using equation (1). Equation (1) in, M The flow rate of the sprayed absorbent is expressed in g / m³. 3 ; C The nitrogen oxide concentration (mg / m³) is the concentration of nitrogen oxides when no adsorbent is injected during the furnace start-up and ignition process. 3 ; α The coefficient of catalytic reaction; λ This is the temperature response coefficient; β This is an empirical coefficient; The α It is (0.4~0.6)×10 -3 The value of λ is any value between -0.006 and -0.01; the value of β is any value between 0.05 and 0.07.

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