Gas analysis system, gas analysis method, program for gas analysis, and material gas supply system

Abstract

The present invention stably measures the concentration of a highly reactive hydrocarbon or hydrogen without affecting the flow rate of an analysis device, and comprises: a main flow path 5 through which a sample gas flows; an analysis device 6 which measures the concentration of a hydrocarbon or hydrogen in the sample gas flowing through the main flow path 5; a sub-flow path 7 which diverges from the main flow path 5 upstream of the analysis device 6; and a flow rate adjustment mechanism 8 which is provided to the sub-flow path 7 and adjusts the flow rate of the sample gas in the main flow path 5 upstream of the sub-flow path 7 by adjusting the flow rate of the sample gas flowing through the sub-flow path 7.

Description

Gas analysis system, gas analysis method, gas analysis program, and material gas supply system

[0001] The present invention relates to a gas analysis system, a gas analysis method, a gas analysis program, and a material gas supply system.

[0002] For example, in industrial processes such as petrochemical processes, denitrification processes, or carburizing processes, highly reactive material gases such as acetylene or ethylene are used. In industrial processes, the flow rate of the material gas used in the process is considered to be controlled based on the concentration of a sample gas sampled from the furnace in order to satisfy desired process conditions (for example, keeping the gas concentration in the processing furnace within a desired range).

[0003] For example, as shown in Patent Document 1, in a vacuum carburizing process, feedback control is considered in which the amount of carburizing gas supplied per unit time by the gas supply device is adjusted so that the gas composition inside the furnace is optimal, based on the gas composition inside the furnace determined by irradiating the gas inside the furnace with laser light.

[0004] However, with highly reactive material gases, the sampled gas may decompose, disappear, or change before reaching the analyzer, making it difficult to properly control the flow rate of the material gas used in the process. While increasing the flow rate of the sample gas to the analyzer might be considered to ensure it reaches the analyzer before decomposition, this can introduce the flow rate of the analyzer itself into the measurement results.

[0005] Japanese Patent Publication No. 2008-208395

[0006] Therefore, the present invention has been made in view of the above-mentioned problems, and its main objective is to stably measure the concentration of highly reactive hydrocarbons or hydrogen while reducing the flow rate influence of the analytical instrument.

[0007] In other words, the gas analysis system according to the present invention is a gas analysis system for measuring the concentration of hydrocarbons or hydrogen in a sample gas sampled from a process apparatus using a chemical reaction, and is characterized by comprising: a main channel through which the sample gas flows; an analytical device for measuring the concentration of hydrocarbons or hydrogen in the sample gas flowing through the main channel; a sub-channel branching off from the upstream side of the analytical device in the main channel; and a flow rate adjustment mechanism provided in the sub-channel, which adjusts the flow rate of the sample gas flowing through the sub-channel, thereby adjusting the flow rate of the sample gas flowing through the sub-channel and thereby adjusting the flow rate of the sample gas flowing through the main channel upstream of the sub-channel.

[0008] In such a gas analysis system, a flow rate adjustment mechanism is provided in a sub-channel branching off from the upstream side of the analyzer in the main channel. By adjusting the flow rate of the sample gas flowing through this sub-channel using this mechanism, the flow rate of the main channel upstream of the sub-channel is adjusted. This allows the flow rate of the sample gas sampled from the process equipment to be increased while keeping the flow rate of the sample gas flowing to the analyzer constant. As a result, the concentration of highly reactive hydrocarbons or hydrogen can be stably measured without affecting the flow rate of the analyzer. In addition, the flow rate of the sample gas sampled from the process equipment can be adjusted to an optimal flow rate that does not affect the chemical reactions in the process equipment.

[0009] As for specific embodiments of the flow rate adjustment mechanism, it is conceivable that the flow rate adjustment mechanism comprises a flow rate adjustment valve, such as a needle valve, provided in the sub-flow channel, and a suction pump provided downstream of the flow rate adjustment valve in the sub-flow channel.

[0010] To prevent substances from adhering to and clogging or causing malfunctions in the suction pump, and to appropriately control the flow rate of the sample gas sampled from the process equipment, it is desirable to provide a dust collection filter between the flow rate adjustment valve and the suction pump in the sub-flow channel.

[0011] The main flow path has a sampling section for sampling internal gas from the process apparatus, and it is desirable that the sampling section be made of ceramic. Furthermore, the sampling section is made of a material with low reactivity to hydrocarbons or hydrogen, and can be made of nickel alloys such as Inconel, Hastelloy, or Monel, titanium alloys, or ceramics such as alumina, silicon nitride, silicon carbide, zirconia, or quartz. With this configuration, the material has low reactivity to hydrocarbons or hydrogen, which suppresses the decomposition or reaction of highly reactive hydrocarbons or hydrogen as they pass through the sampling section, and allows for stable measurement of the hydrocarbon or hydrogen concentration.

[0012] Preferably, the sampling unit is inserted into the furnace wall of the processing furnace of the process apparatus. In the furnace wall of the processing furnace of the process apparatus, a temperature difference occurs between the inside and outside, making it easier for highly reactive hydrocarbons or hydrogen to decompose or react as they pass through the furnace wall. In the present invention, since the sampling unit is inserted into the furnace wall, the decomposition or reaction of highly reactive hydrocarbons or hydrogen is suppressed, and the concentration of hydrocarbons or hydrogen can be measured stably.

[0013] The gas analysis system of the present invention further comprises a flow control unit that controls the flow rate adjustment mechanism, and it is desirable that the flow control unit controls the flow rate adjustment mechanism to gradually increase the flow rate of the main flow path upstream of the subflow path. With this configuration, it is possible to set an optimal flow rate that minimizes the flow rate of the sample gas sampled from the process equipment while minimizing the amount of sample gas decomposition. By minimizing the flow rate of the sample gas sampled from the process equipment, the dust collection filter is less likely to become soiled, and the frequency of replacement can be reduced. By minimizing the amount of sample gas decomposition, the concentration of highly reactive hydrocarbons or hydrogen can be measured stably.

[0014] The gas analysis system of the present invention preferably further comprises a flow rate determination unit that determines the set flow rate of the flow rate adjustment mechanism based on the concentration measurement value of the analyzer when the flow rate of the main flow path is gradually increased by the flow rate adjustment mechanism. With this configuration, the flow rate of the sample gas sampled from the process apparatus can be reduced as much as possible while the amount of decomposition of the sample gas can be reduced as much as possible, and the system can be automatically set to an optimal flow rate.

[0015] The gas analysis system of the present invention preferably further comprises a span gas supply path connected to the upstream side of the analyzer in the main flow path and supplying span gas to the analyzer, and an abnormality determination unit that determines an abnormality in the analyzer based on the concentration measurement value of the analyzer when the span gas is flowed through the analyzer. With this configuration, it is possible to distinguish whether the low concentration measurement value of the analyzer is due to the decomposition of the sample gas or due to an abnormality in the analyzer.

[0016] If the process equipment is used for the acetylene carburizing process, it is desirable that the analytical device measures the concentration of acetylene in the sample gas.

[0017] Furthermore, the gas analysis method according to the present invention is a gas analysis method for measuring the concentration of hydrocarbons or hydrogen in a sample gas sampled from a process apparatus using a chemical reaction, characterized in that the sample gas is introduced into an analytical device through a main flow path, the concentration of hydrocarbons or hydrogen in the sample gas is measured by the analytical device, and a flow rate adjustment mechanism is provided in a sub-flow path branched from the upstream side of the analytical device in the main flow path, thereby adjusting the flow rate of the sample gas flowing through the sub-flow path and adjusting the flow rate of the main flow path upstream of the sub-flow path.

[0018] In order to achieve an optimal flow rate that minimizes the flow rate of the sample gas sampled from the process apparatus while minimizing the amount of sample gas decomposition, it is desirable to use the flow rate adjustment mechanism to gradually increase the flow rate of the main channel upstream of the sub-channel, and to determine the set flow rate of the flow rate adjustment mechanism based on the concentration measurement value of the analyzer when the flow rate of the main channel is gradually increased by the flow rate adjustment mechanism.

[0019] It is desirable to supply span gas to the analyzer from a span gas supply channel connected to the upstream side of the analyzer in the main flow path, and to determine any abnormality in the analyzer based on the concentration measurement value of the analyzer when the span gas is flowed through the analyzer. With this configuration, it is possible to distinguish whether the low concentration measurement value of the analyzer is due to the decomposition of the sample gas or due to an abnormality in the analyzer.

[0020] Furthermore, the gas analysis program according to the present invention is a gas analysis program used in a gas analysis system for measuring the concentration of hydrocarbons or hydrogen in a sample gas sampled from a process apparatus using a chemical reaction, wherein the gas analysis system comprises a main channel through which the sample gas flows, an analyzer for measuring the concentration of hydrocarbons or hydrogen in the sample gas flowing through the main channel, a sub-channel branching off from the upstream side of the analyzer in the main channel, and a flow rate adjustment mechanism provided in the sub-channel, and the gas analysis program is characterized in that it provides a computer with the function of a flow rate control unit that adjusts the flow rate of the sample gas in the main channel upstream of the sub-channel by controlling the flow rate adjustment mechanism to adjust the flow rate of the sample gas flowing through the sub-channel.

[0021] Furthermore, the material gas supply system according to the present invention is a material gas supply system that supplies a material gas involved in a chemical reaction to a process device using a chemical reaction, and includes a flow controller that controls the flow rate of the material gas, the gas analysis system described above that measures the concentration of hydrocarbon or hydrogen in a sample gas sampled from the process device, and a control device that inputs a flow rate set value to the flow controller based on the concentration measurement value of the analyzer. With this material gas supply system, it is possible to stably measure the concentration of highly reactive hydrocarbon or hydrogen without affecting the flow rate of the analyzer, so that the supply amount of the material gas supplied to the process device can be appropriately adjusted.

[0022] According to the present invention described above, it is possible to stably measure the concentration of highly reactive hydrocarbon or hydrogen while reducing the flow rate influence of the analyzer.

[0023] It is an overall schematic diagram of a material gas supply system according to an embodiment of the present invention. It is a schematic diagram showing the configuration of the gas analysis system of the embodiment. It is a graph showing a method for determining the set flow rate of the flow adjustment mechanism in the embodiment. It is a cross-sectional view schematically showing the configuration of the sampling unit of the gas analysis system of the embodiment. It is a schematic diagram showing the configuration of the gas analysis system of a modified embodiment. It is a cross-sectional view schematically showing the configuration of the sampling unit of the modified embodiment. It is a diagram schematically showing a configuration having a wavelength calibration cell of the modified embodiment. It is a cross-sectional view showing the mounting structure of the sampling flow path tube of the modified embodiment. It is a schematic diagram showing the configuration of the gas analysis system of the modified embodiment.

[0024] <Embodiment of the Present Invention> Hereinafter, an embodiment of a material gas supply system incorporating the gas analysis system according to the present invention will be described with reference to the drawings. Note that, for any of the drawings shown below, for the sake of clarity, they are schematically drawn with appropriate omissions or exaggerations. The same reference numerals are assigned to the same components, and the description thereof will be omitted as appropriate.

[0025] <Configuration of Material Gas Supply System 100> As shown in Figure 1, the material gas supply system 100 of this embodiment supplies material gases involved in chemical reactions to various devices 200 (hereinafter referred to as process devices 200) that perform process processing using chemical reactions in industrial processes.

[0026] Here, the process apparatus 200 is used in industrial processes such as petrochemical processes, denitrification processes, or carburizing processes. The process apparatus 200 in this embodiment is used in an acetylene carburizing process, and the processing furnace 201 of the process apparatus 200 is, for example, a gas carburizing furnace, and the material gas is a highly reactive gas such as acetylene (C ２ H ２ ) It can raise gas.

[0027] Specifically, the material gas supply system 100 supplies acetylene (C) to the process apparatus 200. ２ H ２ A flow controller (mass flow controller) 2 controls the flow rate of the gas, and acetylene (C) is the component to be measured in the sample gas sampled from the process apparatus 200. ２ H ２ A gas analysis system 3 measures the concentration of acetylene (C) obtained by the gas analysis system 3, and ２ H ２ The system includes a control device 4 that inputs a flow rate set value to a flow rate controller 2 based on the concentration measurement value of )

[0028] The flow controller 2 is a so-called mass flow controller, and is a package of a fluid control valve (not shown), a flow sensor, and a control board, for example, as a single unit. The flow controller 2 then provides feedback control of the opening degree of the fluid control valve based on the deviation between the flow rate set by the control device 4 (described later) and the flow rate of the material gas measured by the flow sensor. Note that the flow controller does not have to be a mass flow controller that controls mass flow rate, but may also control volumetric flow rate.

[0029] This gas analysis system 3 measures the concentration of acetylene (C ２ H ２ ), which is a highly reactive component in the sample gas sampled from the process device 200. In this embodiment, the gas analysis system 3 measures the concentration of acetylene (C ２ H ２ ) in the sample gas in real time. The specific configuration of the gas analysis system 3 will be described later.

[0030] The control device 4 inputs a flow rate set value to the flow controller 2 based on the measured concentration value of acetylene (C ２ H ２ ) obtained by the gas analysis system 3. Specifically, the control device 4 determines the flow rate set value input to the flow controller 2 by feedback control based on the deviation between the concentration set value of acetylene (C ２ H ２ ) gas (material gas) set by the operator and the measured concentration value of acetylene (C ２ H ２ ) obtained by the gas analysis system 3.

[0031] The control device 4 includes at least one of an analog electric circuit composed of a buffer, an amplifier, etc., a digital electric circuit composed of a CPU, a memory, etc., and an AD converter, a DA converter, etc. that mediate between these analog / digital electric circuits. The control device 4 may be configured using, for example, a PLC (Programmable Logic Controller).

[0032] <Specific Configuration of Gas Analysis System 3> Next, the specific configuration of the gas analysis system 3 will be described with reference to FIG. 2.

[0033] The gas analysis system 3 includes a main flow path 5 through which the sample gas sampled from the process device 200 flows, an analyzer 6 that measures the concentration of acetylene (C ２ H ２ ) in the sample gas flowing through the main flow path 5, a sub-flow path 7 that branches from the upstream side of the analyzer 6 in the main flow path 5, and a flow rate adjustment mechanism 8 provided in the sub-flow path 7.

[0034] The main channel 5 samples the internal gas from the processing furnace 201 of the process apparatus 200 and introduces the sampled gas into the analyzer 6. Specifically, the main channel 5 has a sampling unit 51 that samples the internal gas from the processing furnace 201 of the process apparatus 200. The sampling unit 51 is inserted into the furnace wall 202 of the processing furnace 201. The specific configuration of the sampling unit 51 will be described later.

[0035] Furthermore, the main flow path 5 is equipped with a flow regulator 9, such as an orifice, upstream of the analyzer 6, and a suction pump 10 downstream of the analyzer 6. These allow the flow rate of the sample gas introduced into the analyzer 6 to be adjusted to a constant level. In addition, a dust collection filter 11 may be provided upstream of the flow regulator 9 in the main flow path 5, or a dust collection filter 12 may be provided between the flow regulator 9 and the analyzer 6.

[0036] Furthermore, a span gas supply channel 13 is connected to the main channel 5 to supply a span gas of known concentration for span calibration of the analyzer 6. This span gas supply channel 13 is connected to the upstream side of the analyzer 6 in the main channel 5. In addition, a zero gas supply channel (not shown) is connected to the main channel 5 to supply zero gas for zero calibration.

[0037] Furthermore, the main flow channel pipes forming the main flow channel 5 are made of materials with low reactivity to hydrocarbons or hydrogen, and can be made of nickel alloys such as Inconel, Hastelloy, or Monel, titanium alloys, or ceramics such as alumina, silicon nitride, silicon carbide, zirconia, or quartz. Alternatively, the main flow channel pipes may be metal pipes with a ceramic coating on the inner surface, such as alumina, silicon nitride, silicon carbide, zirconia, or quartz.

[0038] The analyzer 6 measures acetylene (C ２ H ２The acetylene (C) is measured by absorption spectroscopy. Specifically, the analyzer 6 uses infrared laser absorption spectroscopy and comprises a measurement cell 61 into which the sample gas is introduced, a laser light source 62 that irradiates the sample gas in the measurement cell 61 with an infrared laser, a photodetector 63 that detects the infrared laser that has passed through the sample gas in the measurement cell 61, and uses the light intensity signal of the photodetector 63 to measure acetylene (C). ２ H ２ The analyzer 6 in this embodiment uses infrared laser absorption modulation (Patent No. 6886507), but it may also use other absorption spectroscopy methods.

[0039] Here, the laser light source 62 is a quantum cascade laser (QCL), a type of semiconductor laser, which emits mid-infrared (4-12 μm) laser light. This laser light source 62 is capable of modulating (changing) its oscillation wavelength by a given current (or voltage). Note that other types of lasers may be used as long as the oscillation wavelength is variable, and the oscillation wavelength may be changed by changing the temperature, etc. Alternatively, the laser light source 62 may be an interband cascade laser (ICL), a type of semiconductor laser, which emits mid-infrared (3-6 μm) laser light.

[0040] Furthermore, the photodetector 63 may be a thermal type photodetector such as a thermopile, or it may be a photodetector using a quantum type photoelectric element such as HgCdTe, InGaAs, InAsSb, or PbSe.

[0041] The signal processing device 64 calculates the absorption signal (absorbance signal) of the gas from the light intensity signal output from the photodetector 63, and extracts characteristic quantities from the absorption signal, thereby determining the presence of acetylene (C ２ H ２ The concentration of acetylene (C) is calculated by this signal processing device 64. ２ H ２The concentration of ) is output to the control device 4 as a concentration measurement value. The signal processing device 64 comprises an analog electrical circuit consisting of a buffer, an amplifier, etc., a digital electrical circuit consisting of a CPU, memory, etc., and an AD converter, DA converter, etc. that mediates between these analog / digital electrical circuits.

[0042] The sub-channel 7 branches off from the main channel 5 between the sampling unit 51 and the analyzer 6. In this embodiment, the sub-channel 7 can carry a flow rate greater than the flow rate of the sample gas flowing downstream of the branching point of the sub-channel 7 in the main channel 5. The sub-channel tube forming the sub-channel 7 may be made of the same material as the main channel tube, or it may be made of a different material, such as stainless steel.

[0043] The flow rate adjustment mechanism 8 adjusts the flow rate of the main channel 5 upstream of the sub-channel 7 by adjusting the flow rate of the sample gas flowing through the sub-channel 7. Here, the flow rate of the main channel 5 upstream of the sub-channel 7 is the sum of the flow rate of the sample gas introduced into the analyzer 6 and the flow rate of the sample gas flowing through the sub-channel 7.

[0044] Specifically, the flow rate adjustment mechanism 8 comprises a flow rate adjustment valve 81 provided in the sub-flow channel 7 and a suction pump 82 provided downstream of the flow rate adjustment valve 81 in the sub-flow channel 7. A dust collection filter 14 is also provided between the flow rate adjustment valve 81 and the suction pump 82 in the sub-flow channel 7.

[0045] In this configuration, it is desirable that the flow rate of the sample gas flowing through the sub-channel 7 be such that the amount of acetylene decomposition in the sample gas flowing through the main channel 5 is minimized, and the dust collection filter 14 is less likely to become soiled (reducing the frequency of replacement).

[0046] <Method for adjusting the flow rate of sample gas in sub-channel 7> Below, the method for adjusting the flow rate of sample gas in sub-channel 7 will be explained with reference to Figure 3, assuming that the flow rate adjustment valve 81 is a needle valve (manual valve).

[0047] The operator operates the needle valve 81 of the flow rate adjustment mechanism 8 to gradually increase the flow rate of the sample gas in the sub-channel 7, thereby gradually increasing the flow rate (total flow rate) in the main channel 5 upstream of the sub-channel 7. Then, based on the concentration measurement value of the analyzer 6 as the total flow rate is gradually increased, the set flow rate of the flow rate adjustment mechanism 8 is determined. Specifically, this is done in the following procedure.

[0048] First, span gas is supplied from the span gas supply passage 13 to the analyzer 6, and based on the concentration measurement value of the analyzer 6 when the span gas is supplied, it is determined whether or not there is a problem with the analyzer 6. If there is a problem with the analyzer 6, maintenance of the analyzer 6 is performed.

[0049] If there is no abnormality in the analyzer 6, with the needle valve 81 closed, the sample gas is introduced into the analyzer 6 to analyze the acetylene (C) in the sample gas. ２ H ２ Measure the concentration of (first measurement).

[0050] Next, the needle valve 81 is opened gradually in multiple steps, and each time, the sample gas is introduced into the analyzer 6, and the acetylene (C) in the sample gas is analyzed by the analyzer 6. ２ H ２ Measure the concentration of (second and subsequent measurements).

[0051] And, at each opening degree of the needle valve 81, acetylene (C ２ H ２ Based on the change in the concentration measurement value, the set flow rate of the flow rate adjustment mechanism 8 (set opening degree of the needle valve 81) is determined. For example, as shown in Figure 3, if the concentration measurement value of the Nth measurement is the same as the concentration measurement value of the previous (N-1)th measurement, the opening degree of the needle valve 81 in the previous (N-1)th measurement is optimal, and that opening degree of the needle valve 81 is set to the set opening degree. In addition, acetylene (C ２ H ２ When the change in the concentration measurement value of ) falls within a predetermined range and a stable state is reached, the opening degree of the needle valve 81 in the first measurement included in that stable state may be set to the set opening degree.

[0052] In the above-described method for adjusting the flow rate of the sample gas in the sub-channel 7, span gas was flowed from the span gas supply passage 13 to the analyzer 6 to determine whether or not there was a problem with the analyzer 6, but this step may be omitted.

[0053] <Specific Configuration of Sampling Unit 51> Next, the specific configuration of the sampling unit 51 will be explained with reference to Figure 4.

[0054] The sampling unit 51 samples the internal gas from the processing furnace 201 of the process apparatus 200. This sampling unit 51 includes a sampling channel 51a through which the sample gas flows, and a cooling fluid channel 51b through which a cooling fluid flows to cool the sample gas flowing through the sampling channel 51a.

[0055] In this embodiment, the sampling unit 51 is inserted into the furnace wall 202 of the processing furnace 201, the sampling channel 51a is provided to penetrate the furnace wall 202 of the processing furnace 201 in the process apparatus 200, and the cooling fluid channel 51b cools the sample gas flowing through the sampling channel 51a, at least within the furnace wall 202.

[0056] Specifically, the sampling unit 51 includes a sampling channel pipe 511 that forms a sampling channel 51a and a cooling fluid channel pipe 512 that forms a cooling fluid channel 51b.

[0057] The sampling channel tube 511 is connected to the main channel tube, and the sampling channel 51a communicates with the main channel 5. In this embodiment, the sampling channel tube 511 is a straight tube that penetrates the furnace wall 202 of the processing furnace 201, and its tip opening 511x opens into the interior of the processing furnace 201. The sampling channel tube 511 may be formed integrally with the main channel tube. The gas sampled by the sampling channel tube 511 (i.e., the temperature inside the processing furnace 201) is, for example, 800 to 900°C.

[0058] The sampling channel tube 511, like the main channel tube, is made of a material with low reactivity to hydrocarbons or hydrogen. For example, it can be made of nickel alloys such as Inconel, Hastelloy, or Monel, titanium alloys, or ceramics such as alumina, silicon nitride, silicon carbide, zirconia, or quartz. Silicon nitride is preferable as a material with high mechanical strength and resistance to thermal shock. The sampling channel tube 511 may also be a metal pipe with a ceramic coating on its inner surface, such as alumina, silicon nitride, silicon carbide, zirconia, or quartz.

[0059] The cooling fluid flow channel pipe 512 has a main cooling channel section 512a that forms a double-walled structure with the sampling channel pipe 511, a cooling fluid supply channel section 512b that supplies cooling fluid to the main cooling channel section 512a, and a cooling fluid outlet channel section 512c that discharges the cooling fluid that has passed through the main cooling channel section 512a. In this embodiment, the cooling fluid is a gas such as air, but it may also be a liquid such as water or oil.

[0060] The main cooling pipe section 512a is provided so as to surround the sampling flow channel pipe 511 and is located inside the furnace wall 202 of the processing furnace 201. This main cooling pipe section 512a is a straight pipe, and cooling fluid is supplied to its interior.

[0061] The cooling fluid supply pipe section 512b supplies cooling fluid to the inside of the main cooling pipe section 512a. By supplying cooling fluid to the inside of the main cooling pipe section 512a, cooling fluid is supplied between the main cooling pipe section 512a and the sampling flow channel pipe 511. This cooling fluid supply pipe section 512b is connected to the main cooling pipe section 512a outside the processing furnace 201. Specifically, the cooling fluid supply pipe section 512b is connected to the end face wall 512a1 located outside the furnace of the main cooling pipe section 512a, and supplies cooling fluid from the outside of the furnace, which is one end of the main cooling pipe section 512a. A cooling fluid source is connected to the cooling fluid supply pipe section 512b, and this cooling fluid source can be, for example, a cooling device such as a chiller, a cooling element such as a Peltier element, or a cooling fan.

[0062] The cooling fluid outlet section 512c is used to discharge the cooling fluid that has passed through the inside of the main cooling pipe section 512a. This cooling fluid outlet section 512c is connected to the main cooling pipe section 512a outside the processing furnace 201. Specifically, the cooling fluid outlet section 512c is connected to the end face wall 512a1 of the main cooling pipe section 512a and extends along the sampling flow channel pipe 511 within the main cooling pipe section 512a, discharging the cooling fluid from the inside of the furnace (the other end) to the outside of the furnace (the one end) of the main cooling pipe section 512a.

[0063] In this sampling unit 51, the sample gas flowing through the sampling channel 51a is cooled by a cooling fluid, and the cooled sample gas flows through the main channel 5 and is introduced into the analyzer 6. The sample gas is cooled to, for example, about 740°C in the sampling unit 51 by the cooling fluid. With this configuration, the highly reactive hydrocarbons or hydrogen can be introduced into the analyzer 6 while suppressing their reaction or decomposition.

[0064] <Effects of this embodiment> According to the material gas supply system 100 of this embodiment configured as described above, a flow rate adjustment mechanism 8 is provided in the sub-channel 7 that branches off from the upstream side of the analyzer 6 in the main channel 5. By adjusting the flow rate of the sample gas flowing through the sub-channel 7 with this flow rate adjustment mechanism 8, the flow rate of the main channel 5 upstream of the sub-channel 7 is adjusted. As a result, the flow rate of the sample gas sampled from the process apparatus 200 can be increased while keeping the flow rate of the sample gas flowing to the analyzer 6 constant. ２ H ２ The concentration of ) can be measured stably. In addition, the flow rate of the sample gas sampled from the process apparatus 200 can be adjusted to an optimal flow rate that does not affect the chemical reaction in the process apparatus 200.

[0065] <Other Embodiments> For example, in the above embodiment, the flow rate adjustment valve 81 of the flow rate adjustment mechanism 8 was a manual valve, but it may also be an automatic valve such as an electromagnetic valve. In this case, as shown in Figure 5, the gas analysis system 3 further includes a flow rate control unit 15 that controls the flow rate adjustment valve 81 of the flow rate adjustment mechanism 8, and the flow rate control unit 15 may control the flow rate adjustment mechanism 8 (flow rate adjustment valve 81) to gradually increase the flow rate of the main flow path 5 upstream of the sub-flow path 7. The gas analysis system 3 may also further include a flow rate determination unit 16 that determines the set flow rate of the flow rate adjustment mechanism 8 based on the concentration measurement value of the analyzer 6 when the flow rate of the main flow path 5 is gradually increased by the flow rate adjustment mechanism 8. Furthermore, the gas analysis system 3 may further include an abnormality determination unit 17 that determines an abnormality in the analyzer 6 based on the concentration measurement value of the analyzer 6 when span gas is flowed through the analyzer 6. The flow rate control unit 15, the flow rate determination unit 16, and the abnormality determination unit 17 are composed of a dedicated or general-purpose computer having a CPU, internal memory, input / output interface, AD converter, etc., and their functions are performed based on a gas analysis program stored in the internal memory.

[0066] Furthermore, if there is no abnormality in the analyzer 6 based on the concentration measurement value of the analyzer 6 when the span gas is flowed through it, a flow meter (not shown) may be installed between the analyzer 6 and the dust collection filter 11 to measure the flow rate and check for clogging of the dust collection filter 11.

[0067] Furthermore, the sampling unit 51 may be configured to lead the cooling fluid that has passed through the main cooling pipe section 512a into the processing furnace 201 of the process apparatus 200, as shown in Figure 6. For example, an opening 512a3 may be formed in the end wall 512a2 of the main cooling pipe section 512a located inside the furnace. Alternatively, an outlet pipe (not shown) may be connected to the opening 512a3, and the cooling fluid may be led out at a position away from the opening of the sampling flow path 51a (tip opening 511x).

[0068] Furthermore, in the sampling unit 51, the cooling fluid channel 51b may cool the sample gas by supplying a cooling gas to the sampling channel 51a and diluting it. In the case of a configuration in which the sample gas is diluted with a cooling gas, the cooling gas may contain a specific component of known concentration (for example, CO2). ２ NO ２ or N ２ O) is added, and the concentration of the specific component is measured using the analyzer 6 to determine the dilution ratio of the sample gas with the cooling gas, and the acetylene (C) in the sample gas is measured. ２ H ２ It is conceivable to calculate the concentration of (the so-called tracer gas method).

[0069] In the above embodiment, when calibrating the wavelength drift of the laser light source 62, a wavelength calibration cell 65 may be used, as shown in Figure 7. This wavelength calibration cell 65 is filled with a reference gas of known concentration (acetylene gas or methane gas of known concentration).

[0070] When performing wavelength calibration of laser light using this wavelength calibration cell 65, the laser light transmitted through the wavelength calibration cell 65 is detected by the photodetector 63, and the wavelength of the laser light emitted from the laser light source 62 is calibrated based on the light intensity signal of the photodetector 63 or the concentration measurement value of acetylene or methane. Specifically, the signal processing device 64 calibrates the wavelength of the laser light emitted from the laser light source 62 based on the peak position (peak wavelength) of the light intensity signal of the laser light transmitted through the wavelength calibration cell 65.

[0071] The wavelength calibration cell 65 shown in Figure 7(a) is installed between the measurement cell 61 and the photodetector 63, and is irradiated with laser light that has passed through the measurement cell 61. This wavelength calibration cell 65 is filled with a reference gas (e.g., methane gas) that has an absorption peak wavelength different from that of the component to be measured (e.g., acetylene).

[0072] The wavelength calibration cell 65 shown in Figure 7(b) is configured such that laser light is irradiated through a beam splitter 66 provided between the laser light source 62 and the measurement cell 61. In this configuration, a separate photodetector 67 is required in addition to the photodetector 63. The wavelength calibration cell 65 is filled with a gas of the component to be measured (e.g., acetylene) or a reference gas (e.g., methane gas) having a different absorption peak wavelength than the component to be measured (e.g., acetylene).

[0073] The wavelength calibration cell 65 shown in Figure 7(c) is positioned between the measurement cell 61 and the photodetector 63 during wavelength calibration, and is retracted from between the measurement cell 61 and the photodetector 63 during sample gas measurement. This wavelength calibration cell 65 is filled with the gas of the component to be measured (e.g., acetylene), or a reference gas (e.g., methane gas) having a different absorption peak wavelength than the component to be measured (e.g., acetylene). In Figure 7(c), a nitrogen gas cell 68 filled with nitrogen gas is positioned between the measurement cell 61 and the photodetector 63 during sample gas measurement.

[0074] In the gas analysis system 3 of the above embodiment, the sampling unit 51 was structured to cool the sample gas with a cooling fluid, but the sampling unit 51 may also be structured in which the sample gas is not cooled with a cooling fluid.

[0075] The sampling section 51 is not limited to a double-pipe structure consisting of a sampling channel pipe 511 and a main cooling pipe section 512a, but may also have a multi-pipe structure such as a triple-pipe or quadruple-pipe structure. Furthermore, an additional cooling pipe may be provided between the sampling channel pipe 511 and the main cooling pipe section 512a.

[0076] Furthermore, the sampling unit 51 may not have a cooling fluid channel 51b. In this case, the sampling unit 51 has a sampling channel tube 511 that forms a sampling channel 51a for sampling the internal gas from the processing furnace 201 of the process apparatus 200. The sampling channel tube 511 is made of a material with low reactivity to hydrocarbons or hydrogen, and can be made of nickel alloys such as Inconel, Hastelloy or Monel, titanium alloys, or ceramics such as alumina, silicon nitride, silicon carbide, zirconia or quartz. Silicon nitride is preferable as a material with high mechanical strength and resistance to thermal shock. The sampling channel tube 511 may also be a metal pipe with a ceramic coating on its inner surface, such as alumina, silicon nitride, silicon carbide, zirconia or quartz.

[0077] In other words, the gas analysis system is a gas analysis system for measuring the concentration of hydrocarbons or hydrogen in a sample gas sampled from a process apparatus using a chemical reaction, and comprises a sampling channel tube that forms a sampling channel through which the sample gas flows, and an analytical device for measuring the concentration of hydrocarbons or hydrogen in the sample gas, wherein the sampling channel tube is made of a nickel alloy such as Inconel, Hastelloy or Monel, a titanium alloy, or a ceramic such as alumina, silicon nitride, silicon carbide, zirconia or quartz.

[0078] Furthermore, in the flow channel tube including the sampling flow channel tube 511, the portion that is above a predetermined temperature, such as the thermal decomposition start temperature of the component to be measured (e.g., acetylene) (for example, 500°C in the case of acetylene), may be made of a ceramic such as alumina, silicon nitride, silicon carbide, zirconia, or quartz. Here, the flow rate sampled by the sampling flow channel tube 511 may be adjusted by a flow rate adjustment unit based on the temperature of the flow channel tube including the sampling flow channel tube 511 or the temperature of the sample gas. This makes it possible to adjust the residence time in the sampling flow channel tube 511 and reduce the thermal decomposition of the component to be measured (e.g., acetylene).

[0079] Alternatively, as shown in Figure 8, the sampling channel tube 511 may be inserted into a pipe (furnace tube 203) formed in the furnace wall 202 of the processing furnace 201. In this case, the open end of the furnace tube 203 and the sampling channel tube 511 are connected by a joint structure Z such as a bore-through joint. By connecting the sampling channel tube 511 to the furnace tube 203 with this joint structure Z, the sampling channel tube 511 is arranged coaxially inside the furnace tube 203.

[0080] Furthermore, the analytical apparatus 6 in the above embodiment may also use an infrared absorption method, such as a detector using non-dispersive infrared absorption (NDIR) or a detector using Fourier transform infrared spectroscopy (FTIR). In addition, the analytical apparatus 6 may be a gas chromatograph or an electrochemical measuring device using a MEMS sensor or the like.

[0081] Although the gas analysis system 100 of the above embodiment was equipped with a sub-channel 7 and a flow rate adjustment mechanism 8, as shown in Figure 9, it may also be configured without the sub-channel 7 and the flow rate adjustment mechanism 8. In this gas analysis system 100, as described above, the sampling channel tube 511 of the sampling unit 51 is made of a material with low reactivity to hydrocarbons or hydrogen. Specifically, the sampling channel tube 511 can be made of nickel alloys such as Inconel, Hastelloy or Monel, titanium alloys, or ceramics such as alumina, silicon nitride, silicon carbide, zirconia or quartz. Alternatively, the sampling channel tube 511 may be a metal pipe with a ceramic coating on its inner surface, such as alumina, silicon nitride, silicon carbide, zirconia or quartz. The main channel tube connected to the sampling unit 51 of the main channel 5 may also be made of ceramic.

[0082] With this configuration, the sampler is made of a material with low reactivity to hydrocarbons or hydrogen, which suppresses the decomposition or reaction of highly reactive hydrocarbons or hydrogen as they pass through the sampling section, allowing for stable measurement of hydrocarbon or hydrogen concentrations. Furthermore, since the sampling section 51 is inserted into the furnace wall 202, it suppresses the decomposition or reaction of highly reactive hydrocarbons or hydrogen, allowing for stable measurement of hydrocarbon or hydrogen concentrations.

[0083] Furthermore, the sampling unit 51 of the main flow path 5 is inserted into and fixed to the furnace wall 202 of the processing furnace 201, and it is conceivable that the tip opening 511x of the sampling unit 51 be configured to extend away from the furnace wall 202, specifically to the central part of the processing furnace 201. With this configuration, the gas being processed in the processing furnace 201 can be directly sampled and its concentration measured. As a result, it becomes easier to control the flow rate of the material gas used in the process to satisfy desired process conditions (for example, keeping the gas concentration in the processing furnace within a desired range).

[0084] Furthermore, in the gas analysis system shown in Figure 9, the flow rate of the sampled gas flowing through the main channel 5 can be increased by increasing the rotation speed of the suction pump 10 located downstream of the analyzer 6, thereby suppressing the decomposition or reaction of highly reactive hydrocarbons or hydrogen. In this configuration, it is conceivable to use an analyzer 6 such as an NDIR, which is less affected by flow rate.

[0085] The light source is not limited to semiconductor lasers; other types of lasers are also acceptable. Any single-wavelength light source with sufficient half-width to ensure measurement accuracy and capable of wavelength modulation can be used. Furthermore, the light source does not necessarily have to be a laser.

[0086] The gas analysis system of the above embodiment includes acetylene (C) in the sample gas. ２ H ２ It was intended to measure the concentration of acetylene (C), but ２ H ２The system may also measure the concentration of hydrocarbons, such as ethylene, which are highly reactive components other than the material gases supplied to the process equipment, or it may measure the concentration of hydrogen, which is a component produced as a result of the reaction of hydrocarbons. In addition, the gas analysis system may measure the concentration of other components produced by the chemical reactions in the process equipment, in addition to the concentration of the material gas supplied to the process equipment.

[0087] Furthermore, various modifications and combinations of the embodiments are permitted, as long as they do not contradict the spirit of the present invention.

[0088] According to the present invention, the concentration of highly reactive hydrocarbons or hydrogen can be stably measured without affecting the flow rate of the analytical instrument.

[0089] 100...Material gas supply system 200...Processing equipment 2...Flow rate controller 3...Gas analysis system 4...Control device 5...Main flow path 6...Analyzer 7...Sub-flow path 8...Flow rate adjustment mechanism 81...Flow rate adjustment valve 82...Suction pump 13...Span gas supply path 14...Dust collection filter 15...Flow rate control unit 16...Flow rate determination unit 17...Anomaly detection unit

Claims

1. A gas analysis system for measuring the concentration of hydrocarbons or hydrogen in a sample gas sampled from a process apparatus using a chemical reaction, comprising: a main channel through which the sample gas flows; an analyzer for measuring the concentration of hydrocarbons or hydrogen in the sample gas flowing through the main channel; a sub-channel branching off from the upstream side of the analyzer in the main channel; and a flow rate adjustment mechanism provided in the sub-channel, which adjusts the flow rate of the sample gas in the main channel upstream of the sub-channel by adjusting the flow rate of the sample gas flowing through the sub-channel.

2. The gas analysis system according to claim 1, wherein the flow rate adjustment mechanism comprises a flow rate adjustment valve provided in the sub-flow channel and a suction pump provided downstream of the flow rate adjustment valve in the sub-flow channel.

3. The gas analysis system according to claim 2, wherein a dust collection filter is provided between the flow rate adjustment valve and the suction pump in the subflow channel.

4. The gas analysis system according to any one of claims 1 to 3, wherein the main flow path has a sampling unit for sampling internal gas from the process apparatus, and the sampling unit is made of ceramic.

5. The gas analysis system according to claim 4, wherein the sampling unit is inserted into the furnace wall of the processing furnace of the process apparatus.

6. The gas analysis system according to any one of claims 1 to 5, further comprising a flow control unit for controlling the flow rate adjustment mechanism, wherein the flow control unit controls the flow rate adjustment mechanism to gradually increase the flow rate of the main flow path upstream of the subflow path.

7. The gas analysis system according to claim 6, further comprising a flow rate determination unit that determines the set flow rate of the flow rate adjustment mechanism based on the concentration measurement value of the analyzer when the flow rate of the main flow path is gradually increased by the flow rate adjustment mechanism.

8. The gas analysis system according to any one of claims 1 to 7, further comprising: a span gas supply path connected to the upstream side of the analyzer in the main flow path and supplying span gas to the analyzer; and an abnormality determination unit that determines an abnormality in the analyzer based on the concentration measurement value of the analyzer when the span gas is flowed through the analyzer.

9. The gas analysis system according to any one of claims 1 to 8, wherein the analytical device measures the concentration of acetylene in the sample gas.

10. A gas analysis method for measuring the concentration of hydrocarbons or hydrogen in a sample gas sampled from a process apparatus using a chemical reaction, comprising: introducing the sample gas into an analyzer through a main channel and measuring the concentration of hydrocarbons or hydrogen in the sample gas using the analyzer; and adjusting the flow rate of the sample gas in the main channel upstream of the sub-channel by providing a flow rate adjustment mechanism in a sub-channel branched from the upstream side of the analyzer in the main channel and adjusting the flow rate of the sample gas flowing through the sub-channel.

11. The gas analysis method according to claim 10, wherein the flow rate of the main channel upstream of the sub-channel is gradually increased using the flow rate adjustment mechanism, and the set flow rate of the flow rate adjustment mechanism is determined based on the concentration measurement value of the analyzer when the flow rate of the main channel is gradually increased by the flow rate adjustment mechanism.

12. The gas analysis method according to claim 10 or 11, comprising supplying span gas to the analyzer from a span gas supply passage connected to the upstream side of the analyzer in the main flow path, and determining an abnormality in the analyzer based on the concentration measurement value of the analyzer when the span gas is flowed through the analyzer.

13. A gas analysis program used in a gas analysis system for measuring the concentration of hydrocarbons or hydrogen in a sample gas sampled from a process apparatus using a chemical reaction, wherein the gas analysis system comprises a main channel through which the sample gas flows, an analyzer for measuring the concentration of hydrocarbons or hydrogen in the sample gas flowing through the main channel, a sub-channel branching off from the upstream side of the analyzer in the main channel, and a flow rate adjustment mechanism provided in the sub-channel, and the gas analysis program provides a computer with the function of a flow rate control unit that adjusts the flow rate of the sample gas in the main channel upstream of the sub-channel by controlling the flow rate adjustment mechanism to adjust the flow rate of the sample gas flowing through the sub-channel.

14. A material gas supply system for supplying material gases involved in a chemical reaction to a process apparatus using a chemical reaction, comprising: a flow rate controller for controlling the flow rate of the material gas; a gas analysis system according to any one of claims 1 to 7 for measuring the concentration of hydrocarbons or hydrogen in a sample gas sampled from the process apparatus; and a control device for inputting a flow rate setting value to the flow rate controller based on the concentration measurement value of the analysis device.

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