JP2000258580A - Method for evaluating performance of inflammable gas- eliminating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate a theoretical inflammable gas elimination speed without creating a test body or any experiment by giving the concentration of a reactive substance at a catalysis active point by determining that a mass flux to the outer surface of a catalyst in a concentration boundary layer and that to the catalyst active point in the pore of a porous solid are balanced. SOLUTION: As factors for affecting the evaluation of an inflammable gas elimination speed, the catalyst reaction speed of an inflammable gas at a catalyst active point, a reactive substance traveling speed from the inside of a main flow to the outer surface of the catalyst, and the reactive substance diffusion speed inside the catalyst when a catalyst cartridge is made of a porous substance. When the reaction speed is fast, a main factor is the migration/diffusion process of the reactive substance up to the catalyst active point. For the travel of the substance to a wall surface in a flow field, the transportation of the reactive substance due to the main flow exceeds the transfer of the substance due to diffusion, so that diffusion on a wall surface concentration boundary layer and that in the porous catalyst substance becomes dominant. Therefore, the inflammable gas elimination speed can be obtained by the diffuison speed of the reactive substance on the wall surface concentration boundary layer and in the porous solid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating the performance of a combustible gas removing apparatus for removing combustible gas by utilizing a catalytic reaction.

[0002]

2. Description of the Related Art Conventionally, as a device for statically removing flammable gas, a device using a catalyst for promoting the recombination of flammable gas has been installed, for example, in a nuclear power plant. Remove combustible gas generated in the container,
It has the effect of suppressing the rise in internal pressure.

FIG. 7 is a perspective view schematically showing a conventional catalytic combustible gas removing apparatus. Hereinafter, as a typical example of use of this combustible gas removing device, a case where this device is installed in a containment vessel will be described. The housing 13 containing the cartridge 12 holding the catalyst 11 has two openings 14a and 14b. The gas in the containment vessel is supplied to the opening 14 b provided below the housing 13.
From the housing 13.

When the concentration of the flammable gas in the atmosphere in the containment vessel rises, a recombination reaction of hydrogen and oxygen in the atmosphere occurs in the casing 13 by the action of the catalyst 11. The gas heated by the reaction heat generated at this time is
Is discharged from an opening 14a provided at the upper part of the frame. In this way, the reaction heat generated in the catalyst 11 forms a natural circulation flow flowing through the inside of the catalytic recombination device.

FIGS. 8A and 8B both show FIGS.
FIG. 3 is a perspective view showing a typical configuration of a cartridge 12 made of a catalyst 11 carried in a housing 13 shown in FIG. FIG.
The cartridge 12A shown in FIG. 8A has a structure in which the catalyst 11 is supported on a porous material 15 formed into a spherical shape. The cartridge 12B shown in FIG. The catalyst 11 was applied.

In this catalytic combustible gas removing apparatus, the hydrogen removal concentration is evaluated for the purpose of evaluating its performance. This evaluation is mainly based on the following evaluation formula.
In the apparatus having the cartridge 12A of FIG. 8A, the hydrogen removal rate is DR _A , and the cartridge 12 of FIG.
When hydrogen removal rate in the apparatus with B and DR _B, DR _A and DR _B are respectively expressed as follows. DR _A = F _scaleA · F _poisonA · F _lowOA · η _A · a _A · C _H2 ^bA · P / T formula (1) DR _B = F _poisonB · F _lowOB · η _B · a _B · C _H2 · (c _B · P + d _B) formula (2) where, DR: hydrogen removal rate _{[kg / s], F scale} , c, d: factor representing a scaling device (factor), F _poison: reduction of the hydrogen removal rate by catalyst poisons F _lowO : Factor for low oxygen concentration, η: Reaction efficiency, a: Hydrogen removal factor determined by experiment, b: Hydrogen removal multiplier determined by experiment, P: Atmospheric pressure, T: Atmospheric temperature. In addition, the suffix A of each factor in each equation is as shown in FIG.
In the cartridge 12A shown in FIG.
(B) corresponds to the cartridge 12B.

The conventional equation for evaluating the rate of hydrogen removal in such a combustible gas removing apparatus uses a factor determined experimentally for a specific catalytic combustible gas removing apparatus to calculate the hydrogen removal rate as a function of the hydrogen concentration. It represents speed. On the other hand, the natural circulation flow rate, which is driven by the buoyancy generated between the catalyst layers due to the heat of the catalyst reaction, is also expressed as a function of the hydrogen concentration, and is hidden behind the experimental factors.

[0008] Such a speed evaluation formula has the advantage that it can be easily used for evaluating the removal rate of combustible gas by a specific catalytic combustible gas removal device.

[0009]

However, in such a speed evaluation formula, when the type of catalyst, the catalyst layer, and the configuration of the entire catalytic combustible gas removing apparatus change, the experimental factors used up to that time are used. There is a problem that it will not be possible.

Further, the conventional speed evaluation formula can be applied only in the range of the atmosphere condition of the experiment in which the experimental factor used in the evaluation formula is obtained. Therefore,
In order to apply to experimental conditions where the experimental factors deviate from the obtained conditions and to evaluate the performance of the new catalytic combustible gas removal equipment, new tests must be performed and new experimental factors must be obtained. Must.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a problem that a mass flux of a combustible gas per unit area (mass flux; also referred to as a mass flux) at a catalytic active point, that is, a catalytic reaction rate, and a catalyst outer surface. The relationship between the mass flux due to the diffusion of combustible gas in the upper concentration boundary layer and the mass flux due to the diffusion of combustible gas through the pores in the porous solid when the catalyst support is a porous solid Focusing on, assuming that these parameters are in an equilibrium state at steady state, theoretically evaluate the flammable gas removal rate,
An object of the present invention is to make it possible to evaluate the performance of a combustible gas removing device without preparing a test body and performing a new experiment.

[0012]

In order to achieve the above object, according to the first aspect of the present invention, a combustible gas recombination catalyst comprising a porous solid is disposed in a housing. In the performance evaluation method of the flammable gas removal device for evaluating the gas removal performance of the flammable gas removal device having a portion,
Regarding the reactants contained in the gas flowing through the combustible gas removing device, the mass flux to the outer surface of the catalyst by the diffusion of the gas in the concentration boundary layer located near the catalyst surface, and the porous solid The mass flux to the active point of the catalyst due to the diffusion of the gas in the pores is in an equilibrium state, and by giving the concentration of the reactant at the catalytic active point, the catalyst of the reactant The concentration on the outer surface is calculated, and the removal rate of the reactant is calculated based on the concentration on the outer surface of the catalyst.

Further, when the catalyst carrier is a porous solid and the catalytic reaction rate of the combustible gas at the catalytically active point is sufficiently higher than the diffusion rate of the combustible gas from the mainstream to the catalytically active point. In addition, assuming a concentration boundary layer of flammable gas on the catalyst surface, the mass flux to the outer surface of the catalyst due to the diffusion of flammable gas in the concentration boundary layer and the diffusion of flammable gas in the pores of the porous catalyst Is assumed to be in a state of equilibrium, and the ratio of the concentration of the flammable gas at the catalytically active point to the concentration in the mainstream is given as a sufficiently small value. The ratio of the concentration at the surface is calculated, and the mass flux of the combustible gas to the catalyst surface is calculated from the ratio and the concentration of the combustible gas in the mainstream, and this mass flux is used as the removal rate of the combustible gas.

According to the second aspect of the present invention, the flammable gas removing device having an opening in which a flammable gas recombination catalyst made of a porous solid is disposed in a housing to evaluate the gas removing performance of the device. In the method for evaluating the performance of a flammable gas removal device, the reactant contained in the gas flowing through the flammable gas removal device, to the outer surface of the catalyst by diffusion of the gas in a concentration boundary layer located near the catalyst surface. The mass flux of the gas to the catalytically active site due to diffusion of the gas in the pores of the porous solid, and the mass flux of the gas at the catalytically active site per unit area in the catalytic pore. Is in an equilibrium state, the concentration of the reactant on the inner surface of the catalyst pores is given to calculate the concentration of the reactant in the main flow of the gas, and the concentration of the reactant in the main flow is calculated based on the concentration in the main flow. Characterized by calculating a speed removed by.

That is, the catalyst carrier is a porous solid,
If the catalytic reaction rate of the combustible gas at the catalytic active point is not negligible with respect to the overall combustible gas removal rate, a flammable gas concentration boundary layer is assumed on the catalyst surface. Mass flux to the outer surface of catalyst due to diffusion of flammable gas, mass flux to active point of catalyst due to diffusion of flammable gas in pores of porous catalyst, and unit area of flammable gas at active point of catalyst Assuming that the per-catalyst reaction rate is in an equilibrium state, the ratio of the concentration of the combustible gas at the catalyst active site to the concentration in the mainstream and the ratio of the concentration of the combustible gas on the outer surface of the catalyst to the concentration in the mainstream are calculated, From this, the concentration of the flammable gas in the mainstream is calculated back, and the mass flux of the flammable gas toward the outer surface of the catalyst is calculated from the ratio of the concentration of the outer surface of the catalyst to the concentration of the flammable gas in the mainstream and the concentration of the flammable gas in the mainstream. Out to the mass flux and removal rate of the combustible gas.

According to the third aspect of the present invention, there is provided a combustible gas removing apparatus having an opening in which a catalyst carrier obtained by applying a combustible gas recombination catalyst on a plate is disposed in a housing. In the method for evaluating the performance of a combustible gas removing device for evaluating the performance, regarding a reactant contained in a gas flowing through the combustible gas removing device, by diffusion of the gas in a concentration boundary layer located near the catalyst surface. The method is characterized in that a mass flux to the catalyst surface is calculated, and a removal rate of the reactant is calculated based on the mass flux to the catalyst surface.

That is, when the catalyst carrier is not a porous solid and the catalytic reaction rate of the combustible gas at the catalytically active point is sufficiently higher than the diffusion rate of the combustible gas from the mainstream to the catalytically active point. Then, assuming a combustible gas concentration boundary layer on the catalyst surface, the mass flux to the catalyst surface due to the diffusion of the combustible gas in the concentration boundary layer is calculated, and this mass flux is used as the removal rate of the combustible gas. It is characterized by the following.

According to the fourth aspect of the present invention, there is provided a gas removal apparatus for a combustible gas removing apparatus having an opening in which a catalyst carrier formed by applying a combustible gas recombination catalyst on a plate is disposed in a housing. In the method for evaluating the performance of a combustible gas removing device for evaluating the performance, regarding a reactant contained in a gas flowing through the combustible gas removing device, by diffusion of the gas in a concentration boundary layer located near the catalyst surface. Assuming that the mass flux to the outer surface of the catalyst and the mass flux per unit area in the catalyst pores of the gas at the catalyst active point are in an equilibrium state, giving the concentration of the reactant on the catalyst surface Calculating the concentration of the reactant in the mainstream of the gas, and calculating the removal rate of the reactant based on the concentration in the mainstream.

That is, when the catalyst support is not a porous solid and the catalytic reaction rate of the combustible gas at the catalytically active site is not negligible with respect to the total combustible gas removal rate, the combustible gas is deposited on the catalyst surface. Assuming a concentration boundary layer of
Assuming that the mass flux to the catalyst surface due to the diffusion of the combustible gas in the concentration boundary layer and the catalytic reaction rate per unit area of the combustible gas on the catalyst surface are in an equilibrium state,
Calculate the ratio of the concentration of flammable gas on the surface of the catalyst to the concentration of flammable gas on the surface of the catalyst. The mass flux of the combustible gas toward the catalyst surface is calculated from the concentration in the mainstream, and this mass flux is used as the removal rate of the combustible gas.

According to the construction of the invention described in claims 1 to 4 above, regardless of the shape of the catalyst or the magnitude of the reaction rate of the target reactant, an appropriate case is taken into consideration. In each case, a formula for evaluating the flammable gas removal rate can be theoretically obtained.

Further, according to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the catalyst poisonous substance contained in the gas flowing through the combustible gas removing device instead of the reactant. And calculating the rate of attachment of the catalyst poison to the catalyst instead of the rate of removal of the reactants.

That is, as a modification of the first aspect of the present invention, the catalyst carrier is a porous solid, and the adsorption speed of the catalyst poison on the inner surface of the catalyst pores is from the mainstream to the inner surface of the catalyst pores. If the poison diffusion rate is sufficiently high compared to the poison diffusion rate, a concentration boundary layer of the catalyst poison is assumed on the catalyst surface, and the mass flux to the outer surface of the catalyst due to the diffusion of the catalyst poison in the concentration boundary layer is calculated. Assuming that the mass flux to the inner surface of the catalyst pore due to the diffusion of the catalyst poison in the pores in the porous catalyst is in an equilibrium state, Given a sufficiently small value as the ratio, calculate the ratio of the concentration of the catalyst poison on the outer surface of the catalyst to the concentration of the catalyst poison in the main flow, and calculate the mass flow of the catalyst poison from the concentration of the catalyst poison in the main flow toward the outer surface of the catalyst. Calculate the bunch, The mass flux and deposition rate to the catalyst of the catalyst poisons.

Alternatively, as a modification of the second aspect of the present invention, the catalyst carrier is a porous solid, and the adsorption speed of the catalyst poison on the inner surface of the catalyst pores is negligible with respect to the entire catalyst poison adhering speed. If this is not possible, a concentration boundary layer of the catalyst poison is assumed on the catalyst surface, and the mass flux to the outer surface of the catalyst due to the diffusion of the catalyst poison in this concentration boundary layer and the catalyst poison in the pores in the porous catalyst Assuming that the mass flux to the inner surface of the catalyst pore due to the diffusion of the substance and the adsorption rate per unit area of the catalyst poison on the inner surface of the catalyst pore are in an equilibrium state, the catalyst for the concentration of the catalyst poison in the mainstream is Calculate the ratio of the concentration on the inner surface of the pores and the ratio of the concentration on the outer surface of the catalyst to the concentration of the catalyst poison in the mainstream. Touch Calculating the mass flux of the catalyst poisons directed from mainstream concentration ratio and catalyst poisons of concentration at the outer surface on the catalyst outer surface to the mass flux and deposition rate to the catalyst of the catalyst poisons.

Alternatively, as a modification of the third aspect of the invention, the catalyst carrier is not a porous solid, and the adsorption speed of the catalyst poison on the catalyst surface is compared with the diffusion speed of the catalyst poison from the mainstream to the catalyst surface. And if it's fast enough,
Assuming a concentration boundary layer of the catalyst poison on the catalyst surface, calculating a mass flux to the catalyst surface due to diffusion of the catalyst poison in the concentration boundary layer, and using the mass flux as a deposition rate of the catalyst poison. .

Alternatively, as a modification of the invention according to claim 4, when the catalyst carrier is not a porous solid and the adsorption speed of the catalyst poison on the catalyst surface is not negligible with respect to the entire catalyst poison attachment speed, Assuming a concentration boundary layer of the catalyst poison on the catalyst surface, the mass flux to the catalyst surface due to the diffusion of the catalyst poison in the concentration boundary layer and the adsorption rate per unit area of the catalyst poison on the catalyst surface are balanced. Calculate the ratio of the concentration of the catalyst poison in the mainstream to the concentration in the mainstream, calculate the concentration of the catalyst poison in the mainstream from this, and calculate the concentration of the catalyst poison in the mainstream with respect to the concentration in the mainstream. The mass flux of the combustible gas toward the catalyst surface is calculated from the ratio of the catalyst poison and the concentration in the mainstream of the catalyst poison, and this mass flux is used as the deposition rate of the catalyst poison.

According to the fifth aspect of the present invention, regardless of the shape of the catalyst or the magnitude of the reaction rate of the target reactant, an appropriate case is taken into consideration and a theoretical Thus, a formula for evaluating the deposition rate of the catalyst poison can be obtained. Further, in the present invention, by reducing the catalytic reaction rate of the flammable gas at the active point of the catalyst when the catalytic reaction rate of the flammable gas at the catalytic active point is not negligible with respect to the overall flammable gas removal rate. In addition, it is preferable to express the decrease in the combustible gas removal rate due to the attachment of the catalyst poison. This makes it possible to theoretically evaluate the decrease in the flammable gas removal rate due to the attachment of catalyst poison when the catalytic reaction rate of the flammable gas at the catalyst active point is not negligible with respect to the overall flammable gas removal rate. it can.

In the present invention, it is preferable to express the decrease in the rate of removing the combustible gas due to the attachment of the catalyst poisonous substance by increasing the concentration of the combustible gas at the active point of the catalyst. This makes it possible to theoretically evaluate a decrease in the combustible gas removal rate due to the attachment of the catalyst poison.

Further, in the present invention, when the catalyst carrier is a porous solid and the catalyst poison is an aerosol, the catalyst fine particles are formed on the basis of a change in the catalyst pore structure due to aerosol deposition inside and outside the catalyst pores. It is preferable to express a decrease in the rate of removing the combustible gas due to the attachment of the catalyst poisonous substance by reducing the mass flux of the combustible gas due to the diffusion in the holes. Accordingly, in such a case, it is possible to theoretically evaluate a decrease in the combustible gas removal rate due to the attachment of the catalyst poisonous substance.

In the present invention, the gas flow path sandwiched between the catalyst layer and the catalyst layer is represented by a single calculation grid, and the mass of combustible gas removed along an axis parallel to the gas flow. It is preferable to express the phenomenon that the flux spatially decreases as an exponential function of the gas flow velocity. As a result, the dependence of the combustible gas removal mass flux on the gas flow velocity and the distance from the catalyst layer gas inlet can be expressed without dividing the catalyst layer into a plurality of calculation grids, and the prediction accuracy of the combustible gas removal rate Can be improved and the calculation time can be shortened.

In the present invention, the flow path of the gas sandwiched between the catalyst layers and the catalyst layers is represented by a single calculation grid, and the mass flux of the catalyst poison adhering mass is set along an axis parallel to the gas flow. It is preferable that the phenomenon of spatial decrease is represented by an exponential function using the gas flux as a parameter of the mass flux. As a result, the dependence of the mass flux of the catalyst poison on the gas flow velocity and the distance from the catalyst layer gas inlet can be expressed without dividing the catalyst layer into multiple calculation grids, and the prediction accuracy of the catalyst poison deposition rate is improved. And the calculation time can be shortened.

In the present invention, it is preferable that the method for evaluating the above-described flammable gas removal rate and the method for evaluating the catalyst poison deposition rate be described in a programming language.
As a result, it is possible to evaluate the flammable gas removal rate and the catalyst poisoning rate using a computer, and by incorporating it into a thermal containment analysis program for a containment vessel or a general-purpose three-dimensional flow analysis program, It is possible to evaluate the performance of the combustible gas removing device interacting with the atmosphere conditions in the containment vessel and evaluate the concentration distribution of the combustible gas.

Alternatively, it is preferable to describe and implement the above-described method for evaluating the flammable gas removal rate and the method for evaluating the catalyst poison deposition rate using spreadsheet software. Thereby, the evaluation of the speed can be easily performed.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) The concept of a method for evaluating the performance of a combustible gas removing apparatus according to a first embodiment of the present invention will be described with reference to FIG. In the present embodiment, the relationship between parameters used for evaluating the combustible gas removal rate and the catalyst poisoning substance deposition rate, which are important in evaluating the performance of the combustible gas removal apparatus, will be described.

In the evaluation of the flammable gas removal rate, factors affecting the flammable gas removal rate include: the catalytic reaction rate of the combustible gas at the catalytically active site; and the reaction from the main stream to the outer surface of the catalyst. Mass transfer rate can be considered. When the catalyst cartridge is made of a porous material as shown in FIG. 8A, in addition to the above two factors, the following factors can be considered: Hereinafter, in the present embodiment, it is assumed that the catalyst cartridge is a porous substance.

When the reaction rate is very high, such as the reaction rate of hydrogen and oxygen combined with a palladium catalyst, the factor controlling the flammable gas removal rate is the transfer / diffusion process of the reactants to the catalytic active point. . Regarding the mass transfer to the wall in the flow field, the transport of the reactant by the main flow far exceeds the mass transfer by the diffusion, and especially the diffusion in the wall concentration boundary layer and the diffusion in the porous catalyst material are dominant. .

Therefore, the combustible gas removal rate can be determined from the diffusion rate of the reactant in the wall concentration boundary layer and the porous solid.

Similarly, regarding the evaluation of the rate of attachment of the catalyst poison, the factors affecting the rate of attachment of the catalyst poison include: the rate of adsorption of the catalyst poison to the inner surface of the catalyst pores; Poison transfer rates are possible. When the catalyst cartridge is made of the porous material shown in FIG. 8 (a), in addition to the above two factors, the catalyst poisoning substance diffusion rate inside the catalyst can be considered.

When the adsorption rate is very high as in the case of physical adsorption, the factor that governs the catalyst poison deposition rate is the transfer and diffusion process of the catalyst poison to the inner surface of the catalyst pores. Regarding the mass transfer to the wall in the flow field, since the transport of the catalyst poison by the main flow far exceeds that by the diffusion, the diffusion in the wall concentration boundary layer and the diffusion in the porous catalytic material are dominant. .

Accordingly, the catalyst poisoning substance deposition rate can be determined from the wall concentration boundary layer and the diffusion rate in the porous solid.

The diffusion rate per unit area of the species i that diffuses through the concentration boundary layer to the surface of the catalyst cartridge, that is, the mass flux (mass flux) MF _bi [kg / m ² s]
Is given by the following equation. MF _bi = α _i (C _mi −C _si ) Equation (3) where α _i : Mass transfer coefficient of chemical species i [m / s] C _mi : Concentration of chemical species i in mainstream [kg / m ³ ] C _si : concentration of chemical species i on the surface of the catalyst cartridge [kg
/ M ³ ]. Further, these, the mass transfer coefficient _{α i α i = D i /} δ formula (4) where D _i: molecular diffusion coefficient of the species ^{i [m 2 / s] δ} : Equivalent diffusion layer thickness [m] It is.

When the suction flow to the surface is present, the physical transfer coefficient α _i ^* [m / s] when the suction flow is present is given by the following equation by the physical transfer coefficient α _i of the above equation (4). Given. ^{_{α i * = α i · P}} / Pb equation (5) where _{Pb = (Pb m -Pb s)} / ln (Pb m / Pb s) (6) where α ^*: to the surface suction is the case Mass transfer coefficient [m / s] Pb _m : Partial pressure in the main stream of background fluid [Pa] Pb _s : Cartridge surface partial pressure of background fluid [Pa]

Here, the chemical species i includes, for example, hydrogen, oxygen, nitrogen, carbon dioxide, iodine, etc. as a reactant or a catalyst poison in an atmospheric gas flowing through the combustible gas removing device. I assume.

On the other hand, the diffusion rate per unit area of the chemical species i per unit area in the porous solid, that is, the mass flux
MF _pi [kg / m ² s] is given by the following equation. _{MF pi = De i · dC i} / dy formula (7) where C _i: concentration of the chemical species ^{i [kg / m 3] y} : diffusion-distance [m] De _i: porous solid cross-sectional area of the chemical species i Effective diffusion coefficient for [m ² / s]

[0044] The effective diffusion coefficient De _i relates porous solid cross-sectional area is given by the following equation. _{De i = Dn i · ε /} τ Equation (8) where, Dn _i: diffusion coefficient in the capillary species i [m
² / s] ε: Porosity of porous solid [-] τ: Flexural modulus [-]

[0045] This, diffusion coefficient Dn _i in the capillary tube,
It is given by the following equation. _{Dn i = 1 / Dk i +} 1 / D i Equation (9)

Dk _i in this equation is the Knudsen diffusion coefficient [m ² / s] of chemical species i, and the following relational expression is known. _{Dk i = 97.0 · re (T} / Mw i) Formula (10) wherein, re: radius of the capillary [m] T: temperature [K] Mw _i: molecular weight species i [kg / kmol]

When the surface diffusion of the catalyst poison adsorbed on the catalyst cannot be ignored, the following equation (11) is used instead of the equation (7). _{MF pi = De i · dC i} / dy + D si · dQ i / dy formula (11) where, Q _i: adsorption amount ^{[kg / m 3], D} si: surface diffusion coefficient [m ² / s] at And the surface diffusion coefficient D _si is given by: D _si = D _si0 · exp [−E _i / (RT)] / (1−θ) where θ: surface coverage, E _i : adsorption potential energy barrier of adsorption species i D _si0 : θ = 0, τ = τ _d0 The surface diffusion coefficient [m ² /
s]

The surface diffusion coefficient when θ = 0 and τ = τ _d0 is as _follows : D _si0 = γ · λ ² / τ _d0 where γ is a constant λ determined by the number of dimensions in the moving direction of the adsorbed species. Average moving distance of the adsorbed species τ: Time required for moving the distance λ τ _d0 : Moving wavelength of the adsorbed species.

When the catalytic combustible gas removal device is operating in a steady state, the mass flux MF _{bi of the} species i flowing into the cartridge surface through the concentration boundary layer and flowing out of the cartridge surface and absorbed by the catalyst Mass flux MF _pi
And an equilibrium state is established. That is, the following equation is satisfied in a steady state. MF _bi = S · MF _pi formula (11) where, S: surface area of porous catalyst sphere per unit area of cartridge surface [−]

From the equations (3) and (7), the equation (11) can be transformed into the following equation. α (C _mi −C _si ) = S · De _i (C _si −C _ci ) / rc Formula (12) where C _ci : concentration of chemical species i at the center of the porous catalyst sphere [kg / m ² ] rc : Radius of porous catalyst sphere [m]

In deriving equation (12), equation (7)
The following equation modified from: MF _pi = De _i · (C _si −C _ci ) / rc Equation (7 ′) was used.

Here, since the porous catalyst is a sphere, the catalytically active point is at the center of the porous catalyst sphere, and the concentration of the species i at this point is C _ci .

FIG. 1 shows the mass flux (mass flux) of the porous catalyst carrier shown in FIG.
It shows the relationship between the concentration of a certain chemical species. In the drawing, the subscript i indicating the chemical species i is omitted. In the drawing, reference numeral 1 denotes the surface of the catalyst cartridge, reference numeral 2 denotes a porous catalyst, and reference numeral 3 denotes a passage between the catalyst cartridges. A layer near the catalyst cartridge surface 1 within a distance δ is defined as a concentration boundary layer. The reactant or catalyst poison in the atmosphere gas flowing between the catalyst cartridges passes through the concentration boundary layer having a width δ, reaches the cartridge surface 1, and further diffuses through the pores into the inside of the catalyst. .

Since the recombination reaction is performed in the course of the diffusion, the relationship between the concentrations of the chemical species i as the reactant at each point is as shown in FIG. 1, and generally, C _ci <C _si <C _mi .

Now, the reaction speed of the flammable gas at the catalyst active point
If the degree is very large, or to the inner surface of the catalyst pores
If the adsorption rate of the catalyst poison is very high,_ciof
The value is very small and can be regarded as zero. Yo
And C satisfying the expression (12)_siValue, ie the catalyst of species i
The concentration on the surface of the cartridge is required. Also, this C
_siDepending on the value, use the formula (3) or (7 ') to
Mass flux of species i diffusing on the surface of the bridge MF_bi 
Flux MF of chemical species i into a porous or porous solid_pi
 Is obtained.

Therefore, the mass flux MF _{i of the} species _i
That is, when the chemical species i is a combustible gas, the combustible gas removal rate [kg
/ S] When the chemical species i is a catalyst poison, the catalyst poison deposition rate [kg
/ S] is as follows. MF _i = MF _bi · Ab Equation (13) = S · MF _pi · Ab where Ab: catalyst cartridge surface area [m ² ]

FIG. 2 shows a result of creating a program for evaluating the hydrogen removal rate using the method according to the present embodiment described above in detail and incorporating the program into a three-dimensional heat-fluid analysis program (solid line). ) And the experimental results (shown as plots). Plot the experimental results,
The analysis result is shown by a solid line. According to this, the analysis result based on the theoretical formula is in good agreement with the experimental result, and it has been confirmed that the present embodiment can accurately predict the hydrogen removal rate.

By calculating the flammable gas removal rate or the catalyst poisoning substance deposition rate from the theoretical formula, an event having a high reaction rate such as a hydrogen recombination reaction of oxygen or a physical adsorption of a catalyst poisoning substance is obtained. With regard to the above, since the speed can be accurately predicted without involving actual analysis equipment, the performance of the combustible gas removing device can be immediately and appropriately evaluated.

(Second Embodiment) A second embodiment of the present invention will be described. In the above-described first embodiment, a method of evaluating a combustible gas removal rate or a catalyst poisoning substance attachment rate for an event having a high reaction rate, assuming that the catalyst alone is a porous substance, has been described. In the present embodiment, the same evaluation is performed for an event having a low reaction rate.

In the evaluation of the flammable gas removal rate, when the reaction rate is low, such as the binding reaction of hydrogen and nitrogen by a ruthenium catalyst, a factor governing the flammable gas removal rate is as follows.
The reaction rate of the combustible gas at the catalytic active point and the transfer / diffusion process of the reactant to the catalytic active point. Regarding the mass transfer to the wall in the flow field, since the transport of reactants by the main flow far exceeds the mass transfer by diffusion, diffusion in the wall concentration boundary layer and diffusion in the porous catalytic material and in the catalytic active site The reaction rate is dominant. Therefore, the flammable gas removal rate can be determined from the diffusion rate in the wall concentration boundary layer and the porous solid and the reaction rate at the catalytically active site.

Similarly, in the evaluation of the deposition rate of the catalyst poisonous substance, when the adsorption rate is low as in the case of chemisorption, the factors governing the deposition rate of the catalyst poison are the adsorption rate of the catalyst poisonous substance on the inner surface of the catalyst pores and the catalyst fineness. This is the process of transfer and diffusion of the catalyst poison to the inner surface of the pore. Regarding the mass transfer to the wall in the flow field, since the transport of the catalyst poison by the main flow far exceeds that by the diffusion, the dominant factors are the diffusion in the wall concentration boundary layer and the diffusion in the porous catalytic material. The rate of diffusion and adsorption to the inner surface of the catalyst pores. Therefore,
From the diffusion rate in the wall concentration boundary layer and the porous solid and the adsorption rate on the inner surface of the catalyst pores, the catalyst poisoning substance attachment rate can be determined.

The mass flux (mass flux) of species i that diffuses through the concentration boundary layer to the surface of the catalyst cartridge
MF _bi is given by equation (3) described in the first embodiment. Also, the species i per unit area in the porous solid
The diffusion rate MF _pi is given by the equation described in the first embodiment.
It is given by (7) or equation (7).

The chemical reaction of combustible gas removal at the catalytically active point is represented by the following chemical reaction formula: i + j → ij + ΔH Formula (15) where i, j: chemical species of the reactant ij: Chemical species ΔH: expressed by heat of reaction, and when the reaction rate coefficient of this reaction is represented by k _r , the removed mass flux (removed mass flux) MF per unit area in the catalyst pores of the chemical species i at the catalytically active site _ri [kg /
m ² · s] is given by the following equation. _{MF ri = V · M cat ·} k r · C ci f · C cj g formula (15) where, C _ci, C _cj: species i, the concentration of the catalyst pores in the surface of the j f, g: Chemistry Order of reaction of species i, j M _cat : mass of catalyst [kg] V: reciprocal of specific surface area of catalyst [kg / m ² ]

[0064] Similarly, the chemical adsorption reaction of the catalyst poisons in the catalytic surfaces inside the pores of the following chemical _{equation: i + S cat → iS cat} + ΔH ' formula (17) where, S _cat: catalytic active surface iS _cat: species ΔH product substance by a chemical adsorption reaction ': is represented by reaction heat, when the chemisorption rate coefficient of the reaction with k _a, species catalytic pores per unit area of the i at the catalyst active sites Removed mass flux (removed mass flux) MF _ri
[Kg / m ² · s] is given by the following equation. _{MF ri = V · M cat ·} k a · C ci h · [S cat] l expression (18) where, [S _cat]: residual ratio h of the catalytic active surface area to the catalyst surface area, l: species i and catalyst Order of the reaction

This [S _cat ] can be considered to be an index that takes a value of 1 when the catalyst is not poisoned at all, and takes a value of 0 when the catalyst is sufficiently poisoned and no longer functions as a catalyst. .

Now, when the catalytic combustible gas removing device is operating in a steady state, the mass flux MF _{bi of the} species i flowing into the cartridge surface through the concentration boundary layer, and Between the mass flux MF _pi absorbed inside the porous catalyst and the mass flux MF _ri per unit catalyst pore area removed by chemical reaction or chemisorption on the inside surface of the catalyst pore. The state is established. Therefore, MF _bi = S · MF _pi = S · MF _ri (19)

That is, α (C _mi −C _si ) = S · De _i · (C _si −C _ci ) / rc = S · V · M _cat · k · C _ci ^f · C _cj ^g Equation (20)

Here, on the outer surface of the catalyst with respect to the concentration in the mainstream,
Of the concentration of the catalyst and the catalyst pores relative to the concentration on the outer surface of the catalyst
The ratio of the concentration on the inner surface was CMS and CSC, respectively.
deep. That is, CMS = C_si / C_mi Formula (21) CSC = C_ci / C_si Equation (22) is used. From the two terms on the right side of equation (20), equation (22) is given by: CSC = (De_i・ C_ci) / (De_i・ C_ci + VM_cat・ K ・ C_ci ^f ・ C_cj ^g • rc) It is transformed to equation (23). Here, the chemical species on the inner surface of the catalyst pore
Concentration C of i and j_ci And C_cj Any value as the value of
When given, the CSC value is calculated by equation (23). this
From the CSC value, according to equation (22), C_si The value of
You.

Similarly, from the left two terms of equation (20), equation (21)
CMS = (α · rc) / {(S · De _i · (1−CSC) + α · rc)} Equation (24) Similarly, when arbitrary values are given as the values of the concentrations C _ci and C _cj of the chemical species i and j on the inner surface of the catalyst pores, the CMS value is calculated by Expression (23).
From this CMS value, the value of C _si is determined by equation (21).

If the _Cmi value is known, the value of _Cci given first is adjusted to _match this.

Thus, C_mi , C_si , C_ci Is the value of
By being decided, MF_bi , MF _pi Or MF_ri
 Is obtained, the equation described in the first embodiment is obtained.
According to (13), the mass flux (mass flux) of chemical species i
Is required.

By calculating the flammable gas removal rate or the catalyst poison adhering rate from the theoretical formula, an event having a low reaction rate such as a hydrogen recombination reaction of nitrogen or a chemical adsorption of a catalyst poison can be obtained. With regard to the above, since the speed can be accurately predicted without involving actual analysis equipment, the performance of the combustible gas removing device can be immediately and appropriately evaluated.

(Third Embodiment) A third embodiment of the present invention will be described. In the above-described first embodiment, a method for evaluating a combustible gas removal rate or a catalyst poisoning substance attaching rate for an event having a large reaction rate, assuming that the catalyst alone is a porous substance, has been described. In the present embodiment, the same evaluation is performed for a case where the catalyst alone is applied on a metal plate.

In the evaluation of the flammable gas removal rate, FIG.
As shown in (b), when the catalyst carrier is not a porous material such as a metal plate, factors that affect the flammable gas removal rate include the catalyzed reaction rate of the flammable gas at the catalytic active point and the catalyst from the mainstream. The rate of reactant transfer to the surface is conceivable. When the reaction rate is very fast, such as the reaction rate of hydrogen and oxygen combined with a palladium catalyst, the factor controlling the flammable gas removal rate is the transfer of reactants to the catalytic active point.
It is a diffusion process. Regarding the mass transfer to the wall surface in the flow field, since the transport of the reactant by the main flow far exceeds the transfer of the material by diffusion, the diffusion in the wall concentration boundary layer becomes dominant. Therefore, the combustible gas removal rate can be obtained from the diffusion rate in the wall concentration boundary layer.

Similarly, when the catalyst carrier is not a porous material such as a metal plate in the evaluation of the catalyst poison adhering speed, the catalyst poison adsorbing speed on the catalyst surface is a factor affecting the catalyst poison adhering speed. Thus, the catalyst poisoning substance transfer rate from the mainstream to the catalyst surface can be considered. When the adsorption speed is very high as in the case of physical adsorption, the factor that governs the catalyst poison deposition rate is the transfer and diffusion process of the catalyst poison to the catalyst surface. Regarding the mass transfer to the wall surface in the flow field, since the transport of the catalyst poison by the main flow far exceeds the material transfer by the diffusion, the diffusion in the wall concentration boundary layer becomes dominant. Therefore, the catalyst poisoning substance deposition rate can be determined from the diffusion rate in the wall concentration boundary layer.

FIG. 3 shows the relationship between the mass flux (mass flux) and the concentration of a certain chemical species in the catalyst carrier obtained by coating the plate surface with the catalyst shown in FIG. 8 (b). . In the drawing, the subscript i indicating the chemical species i is omitted. Reference numeral 4 in the drawing indicates a catalyst cartridge having a surface coated with a catalyst. The reactant or catalyst poison in the atmospheric gas flowing into the inter-catalyst cartridge passage 3 has a width δ.
And reaches the cartridge 1. In this case, the catalyst active point is on the catalyst cartridge 1.

Diffusion through the concentration boundary layer to the catalyst surface
The mass flux of the species i is described in the first embodiment of the present invention.
Is given by equation (3). Of flammable gas at catalytic active site
When the reaction rate is very high, or on the catalyst surface
If the adsorption rate of the catalyst poison is very high,_sivalue
Is very small and can be regarded as 0. Therefore, C _si
= 0, taking into account equation (3) described in the first embodiment.
Et al., Mass flux MF of species i on the cartridge surface_bi
 Is obtained.

Therefore, the mass flux (mass flux) MF _i of the chemical species i is calculated by the equation (13) described in the first embodiment.
Is required. As described above, according to the present embodiment, even when the catalyst is not a porous substance,
The same effects as in the first embodiment can be obtained.

(Fourth Embodiment) A fourth embodiment of the present invention will be described. In the above-described second embodiment, a method for evaluating a combustible gas removal rate or a catalyst poisoning substance attachment rate with respect to an event having a large reaction rate, assuming that the catalyst alone is a porous substance, has been described. In the present embodiment, the same evaluation is performed for a case where the catalyst alone is applied on a metal plate.

In the evaluation of the flammable gas removal rate, FIG.
As shown in (b), when the catalyst support is not a porous material such as a metal plate and has a slow reaction rate such as a binding reaction between hydrogen and nitrogen by a ruthenium catalyst, a factor controlling a combustible gas removal rate. Is the reaction rate of the combustible gas at the catalytically active point and the transfer / diffusion process of the reactant to the catalytically active point. Regarding the mass transfer to the wall surface in the flow field, the transport of the reactant by the main flow far exceeds the mass transfer by diffusion, so that the diffusion in the wall concentration boundary layer and the reaction rate at the catalytically active site become dominant. Therefore,
From the diffusion rate at the wall concentration boundary layer and the reaction rate at the catalytically active point, the combustible gas removal rate can be determined.

Similarly, in the evaluation of the deposition rate of the catalyst poisonous substance, when the catalyst carrier is not a porous substance such as a metal plate but has a low adsorption rate such as chemisorption, the factor which governs the catalyst poisoning rate is the catalyst. It is the adsorption speed of the catalyst poison on the surface and the transfer / diffusion process of the catalyst poison to the catalyst surface. Regarding mass transfer to the wall in the flow field, the transport of catalyst poisons by the main flow far exceeds the mass transfer by diffusion, so the dominant factors are the diffusion in the wall concentration boundary layer and the rate of adsorption on the catalyst surface. is there. Therefore,
From the diffusion rate at the wall concentration boundary layer and the adsorption rate on the catalyst surface, the catalyst poisoning substance deposition rate can be determined.

The mass flux of the chemical species i that diffuses through the concentration boundary layer to the surface of the catalyst cartridge is given by the equation (3) described in the first embodiment.

The removal mass flux per unit area of the catalyst of the chemical species i at the catalytically active point is given by the equation (15) described in the second embodiment. Here, MF _ri is the removal mass flux per unit area of the catalyst of the species i, and C _ci = C
_si .

Similarly, the attached mass flux of the catalyst poison i per unit area of the catalyst is calculated by the equation (1) described in the second embodiment.
Given in 7). Here, MF _ri is the attached mass flux per unit area of the catalyst of the species i, and C _ci = C _si .

When the catalytic combustible gas removing device is operating in a steady state, the mass flux MF _{bi of the} species i flowing into the cartridge surface through the concentration boundary layer and the chemical reaction or chemisorption on the catalyst surface An equilibrium is established with the mass flux MF _ri per unit catalyst area removed by Therefore, MF _bi = S · MF _ri equation (25)

That is, α (C _mi −C _si ) = S · V · M _cat · k · C _Si ^f · C _Sj ^g Equation (26)

When the ratio of the concentration on the catalyst surface to the concentration in the mainstream is defined as CMS, and given arbitrary values for the concentrations C _si and C _sj on the catalyst surface, the CMS is obtained from the equation (26).
Is calculated by the following equation, and the value of C _mi is determined. CMS = α / (S · V · M _cat · k · C _si ^f−1 · C _sj ^g + α) Equation (27)

If the C _mi value is known, the value of C _Si to be given first is adjusted to match this value. C _mi ,
By determining the value of C _si , MF _bi or M
The value of F _ri is obtained, and the mass flux of the species i is obtained from equation (13).

As described above, according to this embodiment, even when the catalyst is not a porous substance, the same effects as those of the second embodiment can be obtained.

(Fifth Embodiment) In the evaluation of the flammable gas removal rate, the decrease in the flammable gas removal rate due to the attachment of the catalyst poison can be evaluated as follows. Expression (15) described in the second embodiment is re-expressed into the following expression (28). In _{MF ri = V · M cat ·} k r · C ci f · C cj g · [S cat] m Formula (28) where, [S _cat]: residual percentage of the catalyst active surface area m: reaction order of

When the catalyst carrier is not a porous substance, the following holds: C _ci = C _si , C _cj = C _sj .

When the residual ratio of the catalytically active surface area decreases due to the adhesion of the catalyst poison, the removal mass flux _MFri due to the reaction of the combustible gas on the catalyst surface decreases, and the reduction of the combustible gas removal rate due to the adhesion of the catalyst poison decreases. Can be evaluated.

Alternatively, the expression (1) in the second embodiment
By applying 5) as it is and increasing the values of C _ci and C _cj , the value of the mass flux MF _ri removed by the reaction of the flammable gas on the catalyst surface is reduced, and the removal of flammable gas by the adhesion of catalyst poison The decrease in speed can be evaluated. Here, the rate of increase of the values of C _ci and C _cj is
It is related to the coverage of the catalytically active site by the catalyst poison.

When the catalyst carrier is a porous substance and the catalyst poison is an aerosol, the reduction in the number of catalytically active sites due to the aerosol directly adhering to the inner surface of the catalyst pores and the aerosol particles blocking the catalyst pores. The two factors of the inhibition of the combustible gas diffusion in the pores of the catalyst by the gas reduce the combustible gas removal rate. Regarding the reduction of the catalytic active point, the equation (2
7) can be evaluated. Regarding the blockage of the catalyst pores, the influence on the combustible gas removal rate is determined by the relationship between the particle size distribution of the aerosol and the catalyst pore size distribution.

The aerosol particles in the atmospheric gas are removed from the gaseous phase with the passage of time by a mechanism such as a containment vessel spray in the reactor containment vessel, a scrubbing in the suppression pool, or a natural deposition. An aerosol having a particle size that is difficult to remove remains.

Therefore, it is assumed that the aerosol particles are monodispersed, and the particle size is defined as ra. Assuming that the distribution of the catalyst pore diameter re is a normal distribution, the probability density function φ (re) of re is expressed by the following equation.

(Equation 1)

When the relationship between the pores and the particle size of the aerosol deposited thereon is re ≦ ra, the pores are closed. Probability of pore closure
fc is calculated by the following equation.

(Equation 2)

On the other hand, when the aerosol is polydisperse and the particle size distribution is a normal distribution, the probability density function φ (ra) of the aerosol particle size ra is expressed by re in Equation (29) as ra and σ _e
Is replaced by σ _a (dispersion factor of the particle size distribution). The pore blocking probability in this case is calculated by the following equation.

(Equation 3)

[0099] By increasing the bending coefficient and the average pore diameter of the catalyst and decreasing the porosity in accordance with the degree of pore blocking probability, changes in the pore structure of the catalyst due to the deposition of aerosol on the surface can be reduced. The effect on the diffusion rate can be evaluated.

(Sixth Embodiment) In the evaluation of the combustible gas removal rate and the evaluation of the catalyst poisoning substance deposition rate, the gas flow path between the catalyst cartridges can be represented by a single calculation grid. In that case, it is necessary to consider a phenomenon that the mass flux indicating the removal rate of the combustible gas or the mass flux indicating the deposition rate of the catalyst poison decreases along the axis parallel to the gas flow.

FIG. 3 shows a change in mass flux when the calculation grid is divided along an axis parallel to the gas flow. The vertical axis of this graph is the reduction rate Rm of the mass flux (mass flux) and is defined below. Rm = ms * / ms Formula (32)

Here, ms is the mass flux to the cartridge surface when the channel between cartridges is simulated by a single calculation grid, and ms * is the surface of the cartridge when the channel between cartridges is divided into 200 grids. Is the mass flux of

According to FIG. 3, when the number of calculation grids is small, the value of the mass flux is overestimated because the concentration distribution in the axial direction parallel to the flow is not accurately reflected. On the other hand, as the number of divisions of the computation grid increases, the mass flux decreases,
When the number of divisions reaches about 200, the mass flux also approaches an almost constant value. The rate at which the mass flux is reduced depends on the magnitude of the mass flux and the velocity of the gas passing between the cartridges.

As an example, FIG. 4 shows the reduction rate of the hydrogen mass flux in the catalytic reaction between hydrogen and oxygen. From this graph, the following equation is obtained as a relationship between the reduction rate Rm of the hydrogen mass flux and the gas flow velocity. Rm = exp (−0.031 / u) Equation (33) where u: gas velocity [m / s]

FIG. 5 shows the rate of decrease in the mass flux of iodine adhering to the catalyst surface. From this graph, the following equation is obtained as the relationship between the reduction rate Rm of the iodine mass flux and the gas flow velocity. Rm = exp (−0.008 / u) Equation (34)

When the flow path between the catalyst cartridges is represented by a single calculation grid, an exponential function represented by the equations (33) and (34) is used to calculate the mass flux depending on the gas flow rate. A reduction can be considered.

[0107]

According to the present invention, by theoretically evaluating the flammable gas removal rate and the catalyst poisoning substance deposition rate, the performance of the flammable gas removal apparatus can be evaluated without creating a new test body and without experimentation. And development costs can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a relationship between parameters used in a first embodiment of the present invention.

FIG. 2 is a graph showing a comparison between an analysis result and an experiment result when the first embodiment of the present invention is used.

FIG. 3 is an explanatory diagram showing a relationship between parameters used in a third embodiment of the present invention.

FIG. 4 is a graph showing a correlation between a calculation grid division number and a mass flux reduction ratio Rm in a sixth embodiment of the present invention.

FIG. 5 is a graph showing a gas flow rate dependency of a hydrogen removal mass flux reduction ratio Rm in a sixth embodiment of the present invention.

FIG. 6 is a graph showing the gas flow velocity dependence of the iodine-attached mass flux reduction ratio Rm in the sixth embodiment of the present invention.

FIG. 7 is a perspective view schematically showing a conventional catalytic combustible gas removing device.

8 (a) and 8 (b) are catalyst cartridges arranged in a conventional combustible gas removing device, where (a) shows a case where the catalyst is a porous solid, and (b) shows a case where the catalyst is on a plate. It is a case where it is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Surface of a catalyst cartridge, 2 ... Porous catalyst, 3 ... Channel between catalyst cartridges, 11 ... Catalyst, 12 ... Cartridge, 13
... housing, 14a, 14b ... opening, 15 ... porous material, 16 ... metal plate.

Claims (5)

[Claims] 1. A method for evaluating the performance of a combustible gas removing apparatus in which a combustible gas recombining catalyst comprising a porous solid is disposed in a housing and the gas removing performance of the combustible gas removing apparatus having an opening is evaluated. In regard to the reactants contained in the gas flowing in the combustible gas removing device, the mass flux to the outer surface of the catalyst by the diffusion of the gas in the concentration boundary layer located near the catalyst surface, the porous Assuming that the mass flux to the active point of the catalyst due to the diffusion of the gas in the pores of the reactive solid is in an equilibrium state, by giving the concentration of the reactant at the catalytic active point, A method for evaluating the performance of a combustible gas removing apparatus, comprising: calculating a concentration on the outer surface of the catalyst; and calculating a removal rate of the reactant based on the concentration on the outer surface of the catalyst. 2. A method for evaluating the performance of a combustible gas removing apparatus in which a combustible gas recombining catalyst comprising a porous solid is disposed in a housing and the gas removing performance of the combustible gas removing apparatus having an opening is evaluated. In regard to the reactants contained in the gas flowing in the combustible gas removing device, the mass flux to the outer surface of the catalyst by the diffusion of the gas in the concentration boundary layer located near the catalyst surface, the porous Assuming that the mass flux to the catalytically active site due to the diffusion of the gas in the pores of the reactive solid and the mass flux per unit area in the catalytic pores of the gas at the catalytically active site are in an equilibrium state, By giving the concentration of the reactant on the inner surface of the catalyst pores, the mainstream concentration of the reactant gas is calculated, and the removal rate of the reactant is calculated based on the mainstream concentration. Of evaluating the performance of combustible gas removal equipment. 3. A combustible gas removal apparatus for evaluating the gas removal performance of a combustible gas removal apparatus having an opening in which a catalyst carrier obtained by applying a combustible gas recombination catalyst on a plate is disposed in a housing. In the apparatus performance evaluation method, regarding the reactants contained in the gas flowing through the combustible gas removal device,
Calculating a mass flux to the catalyst surface due to the diffusion of the gas in the concentration boundary layer located near the catalyst surface, and calculating a removal rate of the reactant based on the mass flux to the catalyst surface. Evaluation method of combustible gas removal equipment. 4. A combustible gas removal apparatus for evaluating the gas removal performance of a combustible gas removal apparatus having an opening in which a catalyst carrier obtained by applying a combustible gas recombination catalyst on a plate is disposed in a housing. In the apparatus performance evaluation method, regarding the reactants contained in the gas flowing through the combustible gas removal device,
The mass flux to the outer surface of the catalyst due to the diffusion of the gas in the concentration boundary layer located near the catalyst surface and the mass flux per unit area in the catalyst pores of the gas at the catalyst active point are balanced. Providing the concentration of the reactant on the surface of the catalyst, calculating the concentration of the reactant in the mainstream of the gas, and calculating the removal rate of the reactant based on the concentration in the mainstream. Evaluation method of combustible gas removal equipment. 5. A catalyst poison contained in a gas flowing through the combustible gas removing device is applied in place of the reactant, and the catalyst poison is applied to the catalyst in place of the reactant removal rate. 5. The method for evaluating the performance of a combustible gas removing apparatus according to claim 1, wherein an adhesion speed is calculated.