JP2020051969A - By-product gas measurement system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a by-product gas measuring system capable of suppressing a delay in measuring the calorific value of a by-product gas and measuring the calorific value of a clean sample gas under appropriate conditions while prolonging the replacement life of a filter. SOLUTION: In a by-product gas measuring system 10, an introduction pipe 21 is connected so as to enter the inside from an outer wall side of a mother pipe 18 through which a by-product gas flows, and a gas introduction port 21a is opened in the mother pipe 18. .. The transfer pipe 29 is connected to the introduction pipe 21 to transfer the sample gas. The discharge pipe 28 is connected to the transfer pipe 29 and is connected so as to enter the inside from the outer wall side of the mother pipe 18, and the gas discharge port 28a is opened in the mother pipe 18. The calorimeter measures the calorific value of the sample gas flowing from the transfer pipe 29 to the branch pipe 25. The cyclone type filter 24 is interposed at a position upstream of the branch position of the branch pipe 25 in the transfer pipe 29. [Selection diagram] Fig. 1

Description

  The present invention relates to a by-product gas measurement system for measuring the calorific value of a by-product gas.

  During the production of steel at an ironworks, by-product gases such as blast furnace gas (BFG), converter gas (LDG: Linz-Donawitz converter Gas), and coke oven gas (COG: Coke Oven Gas) are generated. . The by-product gas is supplied as a fuel gas (working medium) to a gas turbine such as a combined cycle power generation facility.

  By the way, since such a by-product gas has a smaller calorific value than a general fuel gas, when it is applied as a fuel gas, continuous measurement by, for example, a calorimeter is necessary. In addition, since this type of by-product gas contains a large amount of foreign matter such as dust, the amount of heat is measured after the foreign matter is removed and cleaned by a filter.

  Here, an example of a conventional by-product gas measurement system will be described with reference to FIG. As shown in FIG. 4, a conventional by-product gas measurement system 80 includes a sample gas detection tube 82 for extracting a by-product gas as a sample gas from a mother pipe 81 through which the by-product gas flows, and a sample gas detection tube 82 interposed between the sample gas detection tube 82 and the sample gas detection tube 82, respectively. Provided are sample gas stop valves 83 and 84, a calorimeter 92 attached to the sample gas detection tube 82, and a sample gas atmospheric discharge tube 91.

  As shown in FIG. 4, the calorimeter 92 includes a calorimeter internal pipe 87 connected to the sample gas detection pipe 82, first and second filters 85 and 88, a sampling gas pressure reducing valve 86, a calorimeter 89, It has a sample gas exhaust pipe 90 connected to a gas atmospheric discharge pipe 91. The sampling gas from which foreign matter has been removed by each filter and whose pressure has been reduced to an appropriate pressure by the sampling gas pressure reducing valve 86 has its calorie measured by the calorie measuring unit 89, and then passes through the sample gas exhaust pipe 90 and the sample gas atmospheric discharge pipe 91. Released into the atmosphere.

JP 2017-181468 A JP-A-11-173989

  In the case of the above-described conventional by-product gas measuring system 80, the sample gas is taken out from the mother pipe 81 by the sample gas detection pipe 82 having a relatively large diameter, for example, 15 to 25 mm. This caused a delay in the time from when the sample gas reached the calorimeter 92 and when the calorific value was measured. Further, in the conventional by-product gas measurement system 80, since the sample gas is drawn directly from the mother pipe 81 to the calorimeter 92 through the sample gas detection pipe 82, the amount of foreign matter to be removed in the calorimeter 92 is reduced. And the filter replacement cycle was shortened, and it was necessary to apply an electric dust collector and the like.

  As described above, if a delay occurs in the measurement of the calorific value of the sample gas, this causes a relatively large load change in the gas turbine, for example, and in some cases, may cause a gas turbine burner to misfire, This results in the gas turbine stopping. In addition, the shortening of the above-described filter replacement cycle results in a decrease in the original performance of the filter before replacement, and a drop in the flow rate of the sample gas and a decrease in the supply pressure due to clogging of the filter. This makes it difficult to measure the calorific value of the sample gas under appropriate conditions using a calorimeter.

  An object of the present invention is to provide a by-product gas capable of measuring a calorific value of a clean sample gas under appropriate conditions while suppressing a delay in measurement of a calorific value of the by-product gas and extending a replacement life of the filter. To provide a measurement system.

  A by-product gas measurement system according to one embodiment of the present invention includes an inlet pipe, a transfer pipe, a discharge pipe, a branch pipe, a calorimeter, and a cyclone-type filter. The introduction pipe is connected to the mother pipe through which the by-product gas flows so as to enter the inside from the outer wall side, and opens a gas inlet for introducing the by-product gas as a sample gas into the mother pipe. The transfer pipe is connected to the introduction pipe and transfers the sample gas introduced by the introduction pipe. The discharge pipe is connected to the transfer pipe and connected to the mother pipe so as to enter the inside from the outer wall side, and opens a gas discharge port for discharging the sample gas transferred by the transfer pipe into the mother pipe. . The branch pipe branches from the transfer pipe. The calorimeter measures the calorific value of the sample gas flowing from the transfer pipe to the branch pipe. The cyclone type filter is interposed at a position upstream of the branch position of the branch pipe in the transfer pipe.

  ADVANTAGE OF THE INVENTION According to this invention, the by-product gas measurement system which can suppress the delay of the measurement of the calorific value of a by-product gas and can measure the calorific value of a clean sample gas under suitable conditions, prolonging the replacement life of a filter is provided. It is possible to

FIG. 1 is a diagram schematically illustrating a configuration of a by-product gas measurement system according to a first embodiment. FIG. 2 is a diagram schematically illustrating a configuration around a calorimeter provided in the by-product gas measurement system in FIG. 1. The figure which shows roughly the structure of the by-product gas measuring system which concerns on 2nd Embodiment. The figure which shows the structure of the conventional by-product gas measuring system schematically.

Hereinafter, embodiments will be described with reference to the drawings.
<First embodiment>
As shown in FIG. 1, a by-product gas measurement system 10 according to the present embodiment measures a calorific value of a by-product gas supplied as a fuel gas (working medium) to a gas turbine or the like of a combined cycle power generation facility, for example. Things. The by-product gas measurement system 10 includes a transfer pipe 29 including an intake pipe 22 and a return pipe 27, an introduction pipe 21, a first gas stop valve 23, a cyclone separator 24, a branch pipe 25, a second gas stop valve 26, and a discharge. A tube 28 is provided.

  The introduction pipe 21 is connected to the mother pipe 18 through which the by-product gas flows so as to enter the inside from the outer wall side. The introduction pipe 21 opens a gas introduction port 21 a into the mother pipe 18 for introducing a by-product gas flowing in the mother pipe 18 as a sample gas. Further, the mother pipe 18 supplies the by-product gas to the gas turbine side as a fuel gas. Further, the gas introduction port 21a of the above-described introduction pipe 21 extends to the axis in the mother pipe 18, and collects (samples) by-product gas flowing in the mother pipe 18. Note that the outer wall of the introduction pipe 21 is surrounded by the pipe insertion / removal portion 18a.

  The transfer pipe 29 is connected to the introduction pipe 21. The transfer pipe 29 transfers the sample gas introduced by the introduction pipe 21. As shown in FIGS. 1 and 2, the branch pipe 25 is a supply pipe having a diameter of, for example, 10 mm or less, which branches from the transfer pipe 29 and supplies a sample gas to a calorimeter 39 described later. The calorimeter 39 measures the calorific value of the sample gas flowing from the transfer pipe 29 to the branch pipe 25.

  As shown in FIG. 1, the cyclone separator 24 is a cyclone-type filter (first filter) interposed at a position upstream of the branch position of the branch pipe 25 in the transfer pipe 29. The cyclone separator 24 is a custody-free, substantially maintenance-free filter that captures foreign substances in the sample gas transferred through the transfer pipe 29 by centrifugation.

  The discharge pipe 28 is connected to the transfer pipe 29 and connected to the mother pipe 18 so as to enter the inside from the outer wall side. The discharge pipe 28 opens a gas discharge port 28 a for discharging the sample gas transferred by the transfer pipe 29 into the mother pipe 18. The gas outlet 28a of the discharge pipe 28 extends to the axis in the mother pipe 18, and returns the sample gas transferred by the transfer pipe 29 to the mother pipe 1 as a by-product gas. Here, the introduction pipe 21, the transfer pipe 29, and the discharge pipe 28 form a circulation flow path that circulates from the gas introduction port 21 a to the gas discharge port 28 a while circulating through the branch positions of the cyclone separator 24 and the branch pipe 25. .

  The first gas stop valve 23 is an on-off valve provided on the transfer pipe 29 at a position upstream of the cyclone separator 24. The first gas stop valve 23 stops the flow of the sample gas in the transfer pipe 29 when closed. On the other hand, the second gas stop valve 26 is provided on the transfer pipe 29 at a position downstream of the branch position of the branch pipe 25. The second gas stop valve 26 is also an on-off valve for opening and closing the opening in the transfer pipe 29, and stops the flow of the sample gas in the transfer pipe 29 when closed.

  The above-mentioned transfer pipe 29 is composed of the intake pipe 22 and the return pipe 27 as described above. Specifically, one end of the intake pipe 22 is connected to the introduction pipe 21. The other end of the intake pipe 22 is connected to one end of a return pipe 27, and the other end of the return pipe 27 is connected to a discharge pipe 28. The cyclone separator 24 is provided on the intake pipe 22. The branch pipe 25 branches from the intake pipe 22.

  As shown in FIG. 2, the by-product gas measurement system 10 according to the present embodiment further includes a pressure reducing valve 31, a sample gas relief valve 32, a sample gas atmospheric discharge pipe 33, a drain separator 34, a drain trap 35, a sample gas differential A pressure gauge (DPG: Differential Pressure Gauge) 37, sample gas differential pressure gauge main valves 36a and 36b, a second filter 38, and the above-described calorimeter 39 are provided.

  As shown in FIGS. 1 and 2, the branch pipe 25 described above branches off from the transfer pipe 29 (the intake pipe 22) on the downstream side of the cyclone separator 24 and extends, and is provided with a pressure reducing valve 31, a drain separator 34, and a second filter. It is connected to a calorimeter 39 via 38. The pressure reducing valve 31 reduces the pressure of the sample gas flowing through the branch pipe 25 to a pressure at which the measurement by the calorimeter 39 becomes an optimum condition.

  The sample gas atmospheric discharge pipe 33 is further branched from the branch pipe 25. The sample gas relief valve 32 is an on-off valve for preventing the pressure in the branch pipe 25 downstream of the pressure reducing valve 31 from unnecessarily increasing. The sample gas atmosphere discharge pipe 33 discharges the sample gas passing through the opened sample gas relief valve 32 to the atmosphere. That is, the sample gas relief valve 32 and the sample gas atmosphere discharge pipe 33 protect the branch pipe 25 from excessive pressure that can be applied to the inside of the branch pipe 25 downstream of the pressure reducing valve 31.

  The second filter 38 is provided on the branch pipe 25 at a position upstream of the measurement position of the calorimeter 39. The second filter 38 is, for example, a paper type filter that removes minute scale (dust) in the sample gas in order to increase the cleanliness of the sample gas flowing through the branch pipe. The drain separator 34 is provided on the branch pipe 25 on the upstream side of the mounting position of the second filter. The drain separator 34 is a moisture separator that removes moisture in the sample gas flowing through the branch pipe 25. The drain trap 35 stores moisture (drain) removed by the drain separator 34.

  The sample gas differential pressure gauge 37 is provided in a second branch pipe 37a that once branches from the branch pipe 25 upstream of the second filter 38 and rejoins the branch pipe 25 downstream of the second filter 38. ing. On the upstream and downstream sides of the sample gas differential pressure gauge 37 on the second branch pipe 37a, sample gas differential pressure gauge main valves 36a and 36b which are opened when the sample gas differential pressure gauge 37 is operated are provided, respectively. That is, the sample gas differential pressure gauge 37 calculates the pressure difference between the upstream side and the downstream side of the second filter 38 in the branch pipe 25. Thus, the state of clogging of the second filter 38 can be grasped, and it is possible to determine the time to replace the second filter 38.

  Further, since the drain separator 34 removes moisture in the sample gas, it is possible to suppress deterioration of the performance of the second filter 38 of, for example, a paper type. The cyclone separator 24 provided on the transfer pipe 29 (intake pipe 22) on the upstream side of the branch position of the branch pipe 25 allows the relatively clean sample gas from which foreign matter has been removed to pass through the branch pipe 25 through the second pipe 25. Guided to filter 38. Thereby, clogging of the second filter 38 is suppressed, so that the replacement life of the second filter 38 can be extended.

  Here, in the by-product gas measurement system 10 of the present embodiment, the gas introduction port 21a of the introduction pipe 21 is directed to the upstream side of the flow of the by-product gas in the mother pipe 18, as shown in FIG. . More specifically, the portion of the introduction pipe 21 that has entered the mother pipe 18 has a state in which the depth of entry on the upstream side of the flow is shallower than the depth of entry on the downstream side of the flow. Thus, the open end surface of the gas inlet 21a forms an inclined surface.

  On the other hand, the gas outlet 28 a of the discharge pipe 28 is directed to the downstream side of the flow of the by-product gas in the mother pipe 18. More specifically, the portion of the discharge pipe 28 that has entered the mother pipe 18 is in a state where the depth of entry on the upstream side of the flow is deeper than the depth of entry on the downstream side of the flow. The open end surface of the gas outlet 28a forms an inclined surface.

  In the introduction pipe 21 described above, a drawing force of the by-product gas (sample gas) from the gas inlet 21 a into the introduction pipe 21 is generated by the dynamic pressure due to the flow of the by-product gas in the mother pipe 18. On the other hand, in the discharge pipe 28, a drawing force of the sample gas (by-product gas) from the inside of the discharge pipe 28 is generated by the static pressure due to the flow of the by-product gas in the mother pipe 18. A Karman flow or the like can be generated around the gas outlet 28a. From these facts, a large amount of by-product gas (sample gas) is efficiently transferred from the mother pipe 18 to the discharge pipe 28 via the introduction pipe 21, the transfer pipe 29 (the intake pipe 22 and the return pipe 27). Can be circulated.

  Here, as shown in FIG. 1, an angle formed between the above-described cross section along the radial direction of the introduction pipe 21 (the horizontal cross section of the introduction pipe 21) and the opening end face of the gas introduction port 21 a (the opening end face of the gas introduction port 21 a). Is preferably, for example, 30 ° or more and less than 90 °, and more preferably 45 ° or more and 80 ° or less. When the angle α1 is less than 30 °, the dynamic pressure caused by the flow of the by-product gas is less likely to be applied near the gas inlet 21a.

  On the other hand, as shown in FIG. 1, the angle formed between the cross section along the radial direction of the discharge pipe 28 (horizontal cross section of the discharge pipe 28) and the open end face of the gas discharge port 28 a (the inclined surface at the open end face of the gas inlet 21 a). Is preferably, for example, 30 ° or more and 80 ° or less, and more preferably 45 ° or more and 60 ° or less. The angle α2 is an acute angle.

  The gas inlet 21a of the inlet pipe 21 and the gas outlet 28a of the outlet pipe 28 extend (enter) near the axis in the mother pipe 18. In other words, since the flow rate of the by-product gas is high and the dynamic pressure is high near the axis of the mother pipe 18 as compared with the vicinity of the inner wall of the mother pipe 18, the by-product gas is drawn from the gas inlet 21 a into the inlet pipe 21. Power can be increased. Further, since the flow rate of the by-product gas is high and the static pressure is small near the axis of the mother pipe 18 as described above, the drawing force of the sample gas (by-product gas) from the inside of the discharge pipe 28 can be increased. . Further, the above-described introduction pipe 21 and discharge pipe 28, the mother pipe 18, and the transfer pipe 29 (the intake pipe 22 and the return pipe 27) may be configured by a circular pipe or a rectangular pipe. Good. Furthermore, the ratio of the diameters of the inlet pipe 21, the discharge pipe 28, the branch pipe 25, and the mother pipe 18 is, for example, 1/2, 1/5, 6 and the like. Instead of the gas inlet 21a of the inlet pipe 21, the gas inlet of the inlet pipe is connected to the side of the inlet pipe main body (the outer periphery of the inlet pipe main body at a position facing the flow of by-product gas in the mother pipe 18). Surface).

  Further, in the by-product gas measurement system 10 of the present embodiment, as shown in FIG. 1, the introduction pipe 21 and the discharge pipe 28 have at least portions of the mother pipe 18 that enter the inside from the outer wall side, respectively. It has a double tube structure arranged coaxially with each other. That is, the inner diameter of the introduction pipe 21 is configured to be larger than the outer diameter of the discharge pipe 28, and the discharge pipe 28 is coaxially arranged inside the introduction pipe 21 while leaving a gap in the radial direction. . Further, the discharge pipe 28 located inside the introduction pipe 21 is configured such that the gas discharge port 28 a protrudes from the gas introduction port 21 a of the introduction pipe 21.

  The outer diameter of the return pipe 27 connected to the discharge pipe 28 is configured to be smaller than the inner diameter of the intake pipe 22 connected to the introduction pipe 21. At least a part of the return pipe 27 enters the intake pipe 22 from the outer wall side thereof, and at least a part of the return pipe 27 is radially spaced from the inside of the intake pipe 22. It is arranged. Therefore, the sampling gas introduced from the inside of the mother pipe 18 is taken into the intake pipe 22 while passing through the gap between the outer wall of the discharge pipe 28 and the inner wall of the introduction pipe 21. On the other hand, the sampling gas flowing through the return pipe 27 returns to the inside of the mother pipe 18 via the inside of the discharge pipe 28 located inside the introduction pipe 21.

  As described above, the introduction pipe 21 and the discharge pipe 28 have a double-pipe structure, so that the installation space for the components can be effectively utilized, and the connection between the introduction pipe 21 and the discharge pipe 28 and the mother pipe 18 is substantially formed. In this way, it is possible to simplify the connection between the pipes.

  As described above, in the by-product gas measurement system 10 of the present embodiment, the mother pipe 18 is transferred to the mother pipe 18 via the introduction pipe 21, the transfer pipe 29 (the intake pipe 22 and the return pipe 27), and the discharge pipe 28. Since a large amount of sample gas can be circulated by forming a circulating system that returns, the delay in measurement of the amount of heat in the sample gas can be suppressed. This can prevent the gas turbine from being stopped due to, for example, a load fluctuation of the gas turbine. In the by-product gas measurement system 10, the maintenance-free cyclone separator 24 is provided on the transfer pipe 29 upstream of the branch position of the branch pipe 25, so that the sample gas flowing to the calorimeter 39 through the branch pipe 25 is provided. Foreign substances in the interior can be removed.

  In addition to this, by installing the drain separator 34 on the downstream side of the pressure reducing valve 31 for reducing the sample gas to a pressure optimum for the measurement by the calorimeter 39, the second paper-type second paper positioner located further downstream thereof is provided. The replacement life of the filter 38 can be extended. More specifically, although the by-product gas used as a fuel gas for the gas turbine needs to have its inlet pressure raised to about 2 MPa, the by-product gas at the gas turbine inlet is sent in a state close to saturation. Similarly, the sample gas measured in the above is in a state close to saturation, which causes a drain. However, by providing the drain separator 34 described above, the performance of the second filter 38 can be prevented from deteriorating.

  Therefore, according to the by-product gas measurement system 10 of the present embodiment, it is possible to suppress the delay of the measurement of the calorific value of the by-product gas and to reduce the calorific value of the clean sample gas while prolonging the replacement life of the second filter 38 and the like. It can be measured under appropriate conditions.

<Second embodiment>
Next, a second embodiment will be described with reference to FIG. In FIG. 3, the same components as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted. As shown in FIG. 3, the by-product gas measurement system 50 according to the present embodiment includes a transfer pipe 29 including the intake pipe 22 and the return pipe 27 of the by-product gas measurement system 10 according to the first embodiment, and a discharge pipe 28. , A transfer pipe 59 including an intake pipe 52 and a return pipe 57, and a discharge pipe 58.

  That is, in the by-product gas measurement system 50 of the present embodiment, the position where the gas inlet 21 a of the inlet pipe 21 is opened in the mother pipe 18 is such that the gas outlet 58 a of the outlet pipe 58 is opened in the mother pipe 18. It is located on the upstream side of the flow of the by-product gas in the mother pipe 18 from the position where the flow is performed.

  Therefore, according to the by-product gas measurement system 50 of the present embodiment, the degree of freedom in laying out the introduction pipe 21, the discharge pipe 58, the intake pipe 52, and the return pipe 57 is increased, and the structure can be simplified. it can. Further, in the by-product gas measurement system 50, since the introduction pipe 21 is a single pipe, the opening area of the introduction pipe 21 increases, and the gas discharge port 58a is located at a position separated from the gas introduction port 21a. When the by-product gas is introduced and discharged to and from the mother pipe 18, the flow does not easily interfere with each other, whereby the sample gas is preferably circulated through the introduction pipe 21, the transfer pipe 59, and the discharge pipe 58. Can be.

  Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents.

  10, 50: by-product gas measurement system, 18: mother pipe, 21: introduction pipe, 21a: gas introduction port, 22, 52: intake pipe, 24: cyclone separator, 25: branch pipe, 27, 57: return pipe, 28, 58: discharge pipe, 28a, 58a: gas outlet, 29, 59: transfer pipe, 34: drain separator, 35: drain trap, 38: second filter, 39: calorimeter.

Claims (8)

An introduction pipe connected to the mother pipe through which the by-product gas flows so as to enter the inside from the outer wall side, and a gas introduction port for introducing the by-product gas as a sample gas is opened in the mother pipe;
A transfer pipe connected to the introduction pipe and transferring the sample gas introduced by the introduction pipe;
A gas outlet that is connected to the transfer pipe and connected to the mother pipe so as to enter the inside from the outer wall side thereof, and discharges the sample gas transferred by the transfer pipe, is opened in the mother pipe. Drain pipe,
A branch pipe branched from the transfer pipe;
A calorimeter that measures the calorific value of the sample gas flowing from the transfer pipe to the branch pipe,
A cyclone-type filter interposed at a position upstream of a branch position of the branch pipe in the transfer pipe;
By-product gas measurement system equipped with The gas introduction port is directed to the upstream side of the flow of the by-product gas in the mother pipe,
The by-product gas measurement system according to claim 1. The gas outlet is directed downstream of the flow of the by-product gas in the mother pipe.
The by-product gas measurement system according to claim 1. The portion of the introduction pipe that has entered the mother pipe is a state in which the depth of entry on the upstream side of the flow is shallower than the depth of entry on the downstream side of the flow. The open end face forms an inclined surface,
The by-product gas measurement system according to claim 2. The portion of the discharge pipe that has entered the mother pipe is a state in which the depth of entry on the upstream side of the flow is deeper than the depth of entry on the downstream side of the flow, and The open end face forms an inclined surface,
The by-product gas measurement system according to claim 3. The introduction pipe and the discharge pipe have a double pipe structure in which at least portions of the mother pipe that enter the inside from the outer wall side thereof are coaxially arranged with each other.
The by-product gas measurement system according to any one of claims 1 to 5. The position where the gas inlet is opened in the mother pipe is located on the upstream side of the flow of the by-product gas in the mother pipe from the position where the gas outlet is opened in the mother pipe.
The by-product gas measurement system according to any one of claims 1 to 5. A second filter that is provided on the branch pipe upstream of a measurement position of the calorimeter and removes scale in the sample gas flowing through the branch pipe;
A moisture separator provided on the branch pipe upstream of a mounting position of the second filter, for removing moisture in the sample gas flowing through the branch pipe;
The by-product gas measurement system according to any one of claims 1 to 7, further comprising:

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