JP5311412B2 - Sampling gas decompression device - Google Patents

Description

  The present invention relates to a sampling gas decompression device, and is particularly useful when applied to sampling gaseous substances in high-temperature, high-pressure gas.

  Sampling is performed in which a part of the gas is collected and analyzed for the purpose of analyzing a gaseous substance in a gas flowing through pipe lines (parent pipes) in various plants. When the gas flowing through the pipe to be sampled is a high pressure, the sampling gas collected from this gas is depressurized to a predetermined pressure (for example, normal pressure), and then a gas containing an absorption liquid of a gaseous substance A sampling method for collecting and analyzing gaseous substances by supplying a sampling gas to a cleaning bottle is widely used (see Patent Document 1). This is a wet suction method using so-called bubbling, which is usually performed at normal pressure.

  On the other hand, when high-temperature and high-pressure gas such as gas from an integrated coal gasification combined cycle (IGCC) facility is used for sampling, the high-temperature and high-pressure sampling gas immediately after sampling is analyzed for bubbling or the like. When the pressure is reduced, the amount of pressure reduction is large. Therefore, when the pressure reduction is abruptly performed, the gaseous components in the sampling gas agglomerate and adhere to an intermediate pipe or the like. Therefore, it is necessary to perform such pressure reduction as gently as possible.

  However, in order to gradually reduce the high-temperature and high-pressure sampling gas to a predetermined pressure, a new problem arises that the size of the decompression device is increased.

  For example, Patent Literature 2 discloses a sample sampling device of a power plant that can reduce the pressure of a sample over a wide range without increasing the pressure reducing means, and this is in the axial direction of the sample liquid flow path. Since the core wire disposed in the axial direction is moved in the axial direction to adjust the cross-sectional area of the flow channel between the outer peripheral surface of the core wire and the inner peripheral surface of the sample flow passage, It must be long in the axial direction.

Japanese Patent Application No. 9-218141 JP 2008-128780 A

  In view of the above prior art, the present invention provides a sampling gas decompression device that can gradually reduce the pressure without condensing gaseous substances contained in the sampling gas and at the same time contribute to downsizing of the device. Objective.

The first aspect of the present invention for achieving the above object is as follows:
In a sampling gas decompression device for reducing the pressure to a predetermined pressure by flowing a sampling gas containing a gaseous substance to be sampled collected from a pipeline through which gas flows through a sampling means,
While having a decompression pipeline configured by spirally winding a pipeline for circulating the sampling gas ,
The decompression pipe is formed by concentrically connecting a relatively large-diameter pipe wound spirally and a relatively small-diameter pipe wound spirally inside the spiral formed by the pipe. The sampling gas decompression apparatus is characterized in that it is disposed and connected at one end thereof to form one continuous conduit .

  According to this aspect, since the pipe is wound spirally, the pipe length can be easily increased without increasing the axial dimension.

As a result, even if the sampling gas is at a high pressure, the pressure can be reduced well to a predetermined pressure (for example, normal pressure) without increasing the size of the apparatus. Furthermore, according to this aspect, it is only necessary to secure a required pipe length with a double pipe line, so that further downsizing of the apparatus can be realized.

The second aspect of the present invention is:
The sampling gas decompression apparatus according to the first aspect , wherein the sampling gas collected by the sampling means is heated with the sampling gas flowing through the decompression pipeline so that the gaseous substance does not adhere to the decompression pipeline. A sampling gas decompression apparatus comprising a heating means for performing the above-described operation.

  According to this aspect, the temperature drop due to the decompression of the sampling gas taken into the decompression device can be made as gradual as possible, and the cooling pipe line due to the condensation of the gaseous substance contained in the sampling gas can be made. Adhesion to the inner peripheral surface can be satisfactorily prevented.

  According to the present invention, the pressure of the sampling gas is reduced to a predetermined pressure by the decompression pipe configured by spirally winding the pipe through which the sampling gas is circulated, leading to an increase in the size of the apparatus. In addition, it is possible to easily secure a predetermined pipe length for pressure reduction. As a result, the high-pressure sampling gas is reduced to a predetermined low pressure, and is suitable for application to a sampling device that analyzes gaseous substances contained in the sampling gas.

It is a block diagram which shows the decompression device which concerns on embodiment of this invention with the sampling apparatus to which this is applied. It is a figure which extracts and shows the sampling part in the sampling apparatus shown in FIG. 1, (a) is a longitudinal cross-sectional view, (b) is an AA 'arrow view, (c) is a BB' arrow view. It is. It is a schematic block diagram which shows the decompression device which concerns on other embodiment of this invention. It is a schematic block diagram which shows the pressure reduction apparatus which concerns on other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a decompression device according to an embodiment of the present invention together with a sampling device to which the decompression device is applied. As shown in the figure, the sampling apparatus can be suitably applied to a plant in which high-temperature and high-pressure gas flows, for example, a coal gasification combined power generation facility. Of course, the plant to which the sampling device according to the present embodiment is applied is not limited to the combined coal gasification combined power generation facility. It is generally applicable to sampling a high-pressure sampling gas from a pipeline through which high-pressure gas flows and reducing the sampling gas to a predetermined low pressure. At this time, the larger the amount of reduced pressure, the more effective. Incidentally, the gas flowing through the pipeline in the coal gasification combined power generation facility is a high temperature (eg, 200 ° C.), high pressure (eg, 2 MPa), and high dust gas. Therefore, the sampling apparatus to which the decompression apparatus according to the present embodiment is applied is designed to concentrate and collect gaseous substances by reducing the sampling gas at a high pressure (for example, 2.0 MPa) to normal pressure (0.1 MPa). .

  As shown in FIG. 1, the sampling apparatus includes a pipe 1 that is a mother pipe through which coal gasification gas in a coal gasification combined cycle facility circulates, a sampling unit 2 that is disposed in the pipe 1, and a decompression device 3. And a gaseous substance absorbing portion 4.

  Among these, the sampling unit 2 has a filter (not shown in FIG. 1; the same applies hereinafter) disposed so that the opening surface extends along the axial direction of the pipe 1, which will be described in detail later. In addition, a part of the gas is sucked as a sampling gas through the filter at a filtration rate smaller than the gas flow rate.

  The decompression device 3 according to the present embodiment introduces the sampling gas collected by the sampling unit 2 and decompresses it to a predetermined pressure (usually normal pressure). Incidentally, in the present embodiment, the pressure on the outlet side of the pressure regulating valve 5 (for example, 1.5 MPa) is reduced to normal pressure (0.1 MPa). Such decompression is realized by forming the decompression pipeline 3a in a spiral shape and introducing a sampling gas into the decompression pipeline 3a. In this way, by forming the decompression pipe line 3a in a spiral shape, it is possible to reduce the length of the axial direction as much as possible and to reduce a large pressure. In this case, the length of the decompression pipe line 3a is It is determined by the filtration rate in the filter of the sampling unit 2 (this point will be described in detail later). The decompression device 3 is covered with a sampling pipe 7 from the sampling unit 2 to the decompression device 3 and a sampling pipeline 8 from the decompression device 3 to the gaseous substance absorption unit 4, and the outer periphery thereof is covered with a container 6. Gaseous substances contained in the sampling gas are heated so as not to adhere to the inner peripheral surfaces of the decompression pipe 3a and the sampling pipes 7 and 8 by adiabatic expansion. More specifically, the space between the container 6 and the decompression pipe 3a and the sampling pipes 7 and 8 is supplied with steam at a predetermined temperature from the steam supply section 9 through the steam supply pipe 15 and the inlet side opening / closing valve 16. Is supplied and charged. On the other hand, steam or the like whose temperature has decreased is discharged to the outside through the steam discharge pipe 17 and the outlet-side opening / closing valve 18, and the space is always maintained at a constant temperature by supplying new steam. It has become.

  Here, the inner peripheral surface of the sampling system pipe line with which the sampling gas comes into contact, that is, the inner peripheral surfaces of the sampling pipe lines 7 and 8 and the decompression pipe line 3a are processed with Sulfinate (registered trademark). This prevents gaseous substances from adhering to the inner peripheral surfaces of the sampling pipes 7 and 8 and the decompression pipe 3a.

  The gaseous substance absorption part 4 extracts and collects a gaseous substance from sampling gas, and is comprised as a wet absorption part in this form. That is, although illustration is omitted, the gaseous substance is concentrated and collected in the absorbing liquid by circulating a sampling gas through a glass gas suction bottle containing the absorbing liquid of the gaseous substance.

  The pressure adjusting valve 5 is disposed between the sampling unit 2 and the decompression device 3 in the sampling line 7 and is adjusted so that the pressure of the sampling gas flowing into the decompression device 3 is constant (for example, 1.5 MPa). doing. That is, the pressure of the coal gasification gas flowing through the pipe line 1 varies depending on the operating state and the like. Even if the pressure of the coal gasification gas varies in this way, the pressure of the sampling gas flowing into the decompression device 3 is kept constant. Adjust.

  The steam supply unit 9 supplies steam to the sampling unit 2 or the decompression device 3 via the three-way valve 10 disposed between the pressure regulating valve 5 and the decompression device 3 in the sampling pipe line 7 to obtain the sampling unit 2. The filter or the pressure reducing line 3a of the pressure reducing device 3 is also cleaned.

  Thus, although steam was used as a cleaning agent in this embodiment, the present invention is not limited to this. For example, it may be cleaned with nitrogen gas or the like. However, some equipment has a steam source. In this case, it is reasonable to use steam. Incidentally, in the case of a combined coal gasification combined power generation facility, steam can be easily obtained from, for example, a steam turbine.

  The bypass line 11 distributes excess sampling gas out of the sampling gas discharged from the sampling line 8 of the decompression device 3 by bypassing the gaseous substance absorbing unit 4. Here, a bypass valve 12 is disposed in the middle of the bypass pipe 11 so that the sampling gas bypasses the gaseous substance absorbing unit 4 by opening the bypass valve 12 (usually in an open state). It has become. The other bypass line 13 is for bypassing the sampling gas so as to avoid the inflow of the sampling gas into the gaseous substance absorber 4 when the outlet pressure of the decompression device 3 exceeds a predetermined value for some reason. Therefore, a safety valve 14 is disposed in the middle of the bypass line 13, and the sampling gas bypasses the gaseous substance absorbing unit 4 by opening the safety valve 14. The sampling gas that has bypassed the gaseous substance absorbing section 4 by the bypass pipes 11 and 13 is merged with the coal gasification gas flowing through the pipe 1 on the downstream side.

  According to such a sampling device, the filter is disposed so that the opening surface is along the axial direction of the pipe line 1 through which the coal gasification gas of high temperature, high pressure, and high dust flows, and at a filtration rate smaller than the flow rate of the gas. Since a part of the gas is sucked as the sampling gas through the filter, most of the dust flows along the pipe 1 together with the gas. As a result, the dust hardly adheres to the surface of the filter. It is separated from the filter by the flow and circulated with the gas. As a result, it is possible to prevent the dust from adhering to the filter as much as possible and effectively prevent the accumulation thereof.

  Thus, it is possible to analyze the gaseous substance with high accuracy by preventing the adsorption of the gaseous substance to the dust as much as possible, and at the same time, the continuous sampling is possible, and the gaseous substance can be continuously sampled. .

  Furthermore, in this embodiment, the decompression pipe 3a is spirally wound, so that the pipe length can be easily increased without increasing the axial dimension. As a result, even if the sampling gas is high pressure (for example, 2.0 MPa), the pressure reducing device 3 can be reduced to a predetermined low pressure (for example, normal pressure (0.1 MPa)) without causing an increase in size of the pressure reducing device 3. Can do.

  2A and 2B are diagrams showing an extracted filter portion of the sampling unit in the sampling apparatus, wherein FIG. 2A is a longitudinal sectional view, FIG. 2B is a view taken along the line AA ′, and FIG. 2C is a line BB ′. It is an arrow view. As shown in these drawings, the filter 20 of the sampling unit 2 is disposed so that the opening surface thereof is parallel to the axial direction of the pipe line 1, and the surface thereof is flush with the inner peripheral surface of the pipe line 1. A part of the pipe line 1 is cut out so as to be. More specifically, the filter 20 is fitted into a hole in which a part of the pipe line 1 is cut out so that the opening surface is parallel to the axial direction of the pipe line 1, and the outer periphery side of the filter 20 in this state is Covered with a cover 21 fixed to the pipe line 1. As a result, a space is formed between the outer surface of the filter 20 and the inner peripheral surface of the cover 21, and one end portion of the sampling pipe line 7 is opened in this space. Here, the portions where the sampling gas contacts, such as the inner peripheral surface of the filter 20 and the cover 21, are subjected to the same Sulfinate (registered trademark) processing as the inner peripheral surface of the sampling pipe line 7, etc. It is the structure which can prevent as much as possible.

  In the sampling unit 2 having such a filter 20, the gas flowing through the pipe line 1 is sucked through the filter 20 in a direction orthogonal to the axial direction of the pipe line 1. As a result, part of the gas filtered by the filter 20 flows into the sampling pipe line 7 through the space between the cover 21 and the sampling gas. At this time, it is possible for dust 19 contained in the gas to be deposited on the surface of the filter 20 by making the filtration speed of the sampling gas through the filter 20 sufficiently lower than the flow velocity of the gas flowing through the pipe line 1. It can be prevented as much as possible. When the filtration rate is sufficiently small with respect to the gas flow rate, most of the dust 19 flows along with the gas in a state where it floats in the gas, and even if it adheres to the surface of the filter 20, the sampling pipeline 7 side Since the flow rate of the sampling gas toward (lower side in FIG. 2 (a)) is small, the dust 19 exposed to the gas flow flowing through the pipe line 1 on the filter 20 is peeled off from the filter 20 and becomes a gas flow. It is because it is rejected by riding.

  The filtration speed in the filter 20 at this time is the difference between the pressure on the inlet side and the pressure on the outlet side of the pressure reducing line 3a and the pressure reducing line when the pressure reducing device 3 is formed by the pressure reducing line 3a wound in a coil shape. It is uniquely determined according to the pipe length of 3a. Therefore, when the difference between the pressure on the inlet side and the pressure on the outlet side is specified, the helical pipe length of the decompression pipe 3a should be determined so as to be a pressure difference according to the filtration speed. good.

  In the case of this embodiment in which the pressure on the inlet side is, for example, 1.5 MPa and the pressure on the outlet side is, for example, 0.1 MPa, the difference between the two is 1.4 MPa. What is necessary is just to select the pipe line length according to the desired sampling gas amount from the relationship of the sampling gas amount in an exit. Incidentally, in the case of the above embodiment, the sampling gas filtration rate is set to 0.01 m / sec while the gas flow rate in the pipe line 1 is 10 m / sec. That is, the filtration rate with respect to the gas flow rate is 1/1000.

  As described above, when the filtration rate is reduced to 1/1000 with respect to the flow rate of the high-temperature and high-pressure gas flowing through the pipeline 1, and the pressure is reduced to 1/15 from 1.5 MPa to normal pressure 0.1 MPa. Even so, with the helical decompression pipe 3a according to the present embodiment, it is possible to suppress the lengthening of the duct and perform good decompression. At this time, since the sampling gas to be decompressed is heated while flowing through the decompression line 3a, the gaseous substances contained in the sampling gas due to adiabatic expansion accompanying the decompression are reduced in the decompression line 3a and the sampling line. 7 and 8 can be prevented from adhering to the inner peripheral surface.

  In addition, although the pressure-reduction pipe line 3a in the said embodiment was helically wound once and comprised, it is not restricted to this. For example, a decompression device 30 as shown in FIG. 3 may be used. The decompression device 30 shown in the figure includes a relatively large-diameter decompression pipe 30a wound spirally and a relatively small-diameter decompression spirally wound inside the spiral formed by the decompression duct 30a. The conduit 30b is concentrically arranged, and both ends are connected to each other, and one continuous decompression conduit is accommodated in the container 6. That is, the pressure reducing pipe having a double pipe structure is configured.

  According to this aspect, it is only necessary to secure the necessary pipe length with the double pressure reducing lines 30a and 30b, so that further downsizing of the pressure reducing device 30 can be realized.

  Moreover, in each said embodiment, although the steam was used as a heating means in the decompression devices 3 and 30, it does not restrict to this. For example, as shown in FIG. 4, a heater 60 may be disposed on the outer periphery of the pressure reducing line 3a in the space between the container 6 and the pressure reducing lines 3a, 30a, and the heater 60 may be used as a heating means. Note that the decompression device 31 shown in FIG. 4 (a) has the decompression pipe 3a disposed in the container 6, and the decompression device 32 shown in FIG. 4 (b) has the decompression ducts 30a and 30b in the container 6. Is provided.

  3 and 4, the same parts as those in FIG. 1 or 3 are denoted by the same reference numerals, and redundant description is omitted.

  The present invention can be effectively used in the industrial field of sampling a gaseous substance from a high-pressure gas.

DESCRIPTION OF SYMBOLS 1 Pipe line 2 Sampling part 3,30,31,32 Pressure reducing device 3a, 30a, 30b Pressure reducing line

Claims (2)

In a sampling gas decompression device for reducing the pressure to a predetermined pressure by flowing a sampling gas containing a gaseous substance to be sampled collected from a pipeline through which gas flows through a sampling means,
While having a decompression pipeline configured by spirally winding a pipeline for circulating the sampling gas ,
The decompression pipe is formed by concentrically connecting a relatively large-diameter pipe wound spirally and a relatively small-diameter pipe wound spirally inside the spiral formed by the pipe. A sampling gas decompression device characterized in that the sampling gas decompression device is configured as one continuous pipe line by being disposed and connecting one end portions of both . The sampling gas decompression device according to claim 1 ,
The sampling gas sampled by the sampling means comprises a heating means for heating the sampling gas flowing through the decompression pipe so that the gaseous substance does not adhere to the decompression pipe. Decompressor.