JP5554267B2 - Gas engine system - Google Patents

Description

  The present invention relates to a gas engine system that can grasp the ratio of dust and hydrocarbons in the fuel gas of a gas engine online, and continues stable combustion.

  Conventionally, a gas mixture gas fuel is introduced into the main chamber of the engine so that the gas fuel and the gas mixture gas fuel in the main chamber can be easily ignited in a sub chamber provided adjacent to the main chamber. A sub-chamber system that introduces and mixes, ignites the mixed gas fuel in the sub chamber, and forms a torch toward the main chamber by a flame ejected from a plurality of nozzle holes, and burns the gas mixture fuel in the main chamber A gas engine is known (Patent Document 1).

JP 2009-203952 A

  By the way, in the gas engine, when the calorie of the gas fuel introduced into the sub chamber fluctuates, there is a problem that the stable combustion in the sub chamber is not realized and the combustion of the entire gas engine becomes unstable. Even when it is necessary to control the calorie of the gas fuel in accordance with fluctuations in the in-cylinder temperature, the rotation speed, and the inner cylinder pressure, there is a problem that the calorie cannot be grasped and cannot be controlled.

  In addition, in order to stabilize the calorie of the fuel gas, a buffer tank that homogenizes the gas concentration is provided, but quickly grasps the calorie of the fuel gas online before the gas fuel is burned, The advent of a technique for adjusting the fuel gas according to the grasped calories is required.

Due to the foreign matter, the closed state of the fuel gas supply valve is deteriorated, and a large amount of fuel gas flows in, which may prevent stable combustion of the gas engine.
However, there has been a problem that there is no gas engine system that quickly and continuously measures foreign matter.

  In view of the above problems, the present invention is a gas engine capable of achieving stable combustion by grasping gas composition, dust, and hydrocarbons (HC) by a single device and taking measures based on the results. The problem is to provide a system.

A first aspect of the present invention for solving the above-described problem is a fuel gas supply pipe for supplying fuel gas to a main combustion chamber and a sub chamber of a gas engine, and a laser for the fuel gas in the fuel gas supply pipe. A laser analyzer for measuring the gas composition and the dust concentration of the fuel gas by irradiating light, a first bypass pipe branched to the fuel gas pipe and having a first filter, and a dust concentration of the laser analyzer As a result, there is provided a gas engine system comprising a control means for performing control for introducing fuel gas into the first bypass pipe when the amount of dust exceeds a threshold value .

According to a second invention, in the first invention, the second bypass pipe having the second filter is provided, and the hydrocarbon concentration is obtained by the laser device, and the hydrocarbon concentration is obtained from the result of the hydrocarbon concentration of the laser device. And a control means for controlling the introduction of the fuel gas into the second bypass pipe having the second filter when the value exceeds the threshold value.

According to a third invention, in the first or second invention , the laser analyzer is a laser irradiation device that oscillates a laser fundamental wave, and a wavelength converter that converts the wavelength of the oscillated laser fundamental wave into a first wavelength conversion laser beam. 1 wavelength converter, a wavelength-converted first wavelength-converted laser beam, a measurement unit that irradiates the fuel gas to generate first Raman scattered light, and the generated first Raman scattered light A Raman scattered light detector for measuring, and from the measurement result of the first Raman scattered light, the gas composition of the fuel gas is obtained from the peak signal spectrum of the Raman scattered light, and the concentration of soot in the fuel gas is obtained from the peak signal. The gas engine system is obtained from a baseline excluding the spectrum.

According to a fourth invention, in the second invention , the laser analyzing device includes a laser irradiation device that oscillates a laser fundamental wave, and a first wavelength converter that converts the wavelength of the oscillated laser fundamental wave into a first wavelength-converted laser beam. A wavelength converter, a second wavelength converter that combines the laser fundamental wave and the first wavelength converted laser light, and converts the wavelength of the combined laser light into a second wavelength converted laser light; A measurement region for introducing wavelength-converted laser light and irradiating the fuel gas to generate second Raman scattered light; and a Raman scattered light detector for measuring the generated second Raman scattered light; Based on the measurement result of the Raman scattered light, the gas composition of the fuel gas is obtained from the peak signal spectrum of the second Raman scattered light, and the concentration of soot and hydrocarbons in the fuel exhaust gas is excluded from the peak signal spectrum. Seeking from the line In a gas engine system, wherein the door.

According to a fifth invention, in the second invention , the laser analyzing device includes a laser irradiation device that oscillates a laser fundamental wave, and a first wavelength converter that converts the wavelength of the oscillated laser fundamental wave into a first wavelength-converted laser beam. A wavelength converter, a measurement region for introducing the first wavelength-converted laser light, irradiating the fuel gas to generate the first Raman scattered light, and the laser fundamental wave and the first wavelength-converted laser light are combined. A second wavelength converter that converts the wavelength of the combined laser beam into a second wavelength conversion laser beam, and a second wavelength conversion laser beam, and irradiates the exhaust gas to generate the second Raman scattered light. A measurement region to be generated, and a Raman scattered light detector for measuring the generated first or second Raman scattered light, and the gas composition of the fuel gas is determined based on the measurement result of the first Raman scattered light. When calculated from the peak signal spectrum of Raman scattered light, The concentration of soot in the fuel gas is obtained from the baseline excluding the peak signal spectrum, and the gas composition of the exhaust gas is obtained from the peak signal spectrum of the second Raman scattered light based on the measurement result of the second Raman scattered light. A gas engine system is characterized in that the concentration of soot and hydrocarbons in the fuel gas is obtained from a baseline, and the soot concentration is estimated from the difference between the two.

According to a sixth invention, in any one of the third to fifth inventions, the signal intensity (R ₀ ) of the Raman scattered light of the reference gas existing in the fuel gas is measured in advance, and each time measurement is performed, The signal intensity (R ₁ ) of the Raman scattered light of the reference gas existing in the measurement region is measured, and the obtained R ₀ / R ₁ is set as a calibration constant (K), and each detected signal intensity (X ₁ ) of the peak signal spectrum is measured. ) Multiplied by a calibration coefficient (K = R ₀ / R ₁ ) to obtain a true signal intensity, and a gas composition and a dust concentration (M ₂ ) are calculated from the true signal intensity. It is in.

According to a seventh aspect of the invention, there is provided the gas engine system according to any one of the first to sixth aspects, wherein the irradiated laser beam is in a sheet form.

  According to the present invention, a gas composition can be obtained from a peak signal spectrum of Raman scattered light using a laser beam having a specific wavelength, and a baseline excluding the peak signal spectrum can be obtained as a dust concentration. It is possible to simultaneously measure the gas component, the dust concentration, and the hydrocarbon concentration with the detection device.

FIG. 1 is a schematic diagram of a gas engine system according to a first embodiment. FIG. 2 is a schematic diagram of a gas engine system according to the second embodiment. FIG. 3 is a schematic diagram of a gas engine system according to a third embodiment. FIG. 4 is an exhaust gas measurement chart of the gas engine system according to the first embodiment. FIG. 5 is an exhaust gas measurement chart of the gas engine system according to the second embodiment. FIG. 6 is an exhaust gas measurement chart of the gas engine system according to the second embodiment. FIG. 7-1 is a calibration curve showing the relationship between Mie scattered light intensity and dust concentration at a wavelength of 532 nm. FIG. 7-2 is a calibration curve showing the relationship between Mie scattered light intensity and dust concentration at a wavelength of 355 nm. FIG. 8 is a configuration diagram around the combustion chamber showing the configuration of a gas engine using low-calorie gas as fuel.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  For example, a gas engine that uses low-calorie gas with low methane concentration, such as gasification gas from a gasification furnace, injects the low-calorie gas into a sub chamber and ignites it with a spark plug. The low-calorie which is injected through the air supply port separated from the side of the sub chamber by the spouted flame is ejected to the main combustion chamber through the communication hole connecting the sub chamber and the main combustion chamber The air-fuel mixture in the main combustion chamber formed by the gas is combusted.

  FIG. 8 is a configuration diagram around the combustion chamber showing the configuration of a gas engine using low-calorie gas as fuel. In FIG. 8, an engine (gas engine) denoted by reference numeral 100 is a sub-chamber ignition type four-cycle gas engine using a spark plug, and a piston 102 and a cylinder fitted in a cylinder liner 102a so as to be slidable in a reciprocating manner. A main combustion chamber (hereinafter also referred to as “main chamber”) 101 is formed between the lower surface of the head 105, the upper surface of the piston 102, and the inner surface of the cylinder liner 102a.

The engine 100 includes an air supply port 103 connected to the main combustion chamber 101, an air supply valve 104 that opens and closes the air supply port 103, an exhaust port 106 connected to the main combustion chamber 101, and the exhaust port An exhaust valve 107 for opening and closing 106 is provided.
The exhaust port 106 is connected to a turbine 109 a of an exhaust turbocharger 109 via an exhaust pipe 108. The exhaust gas after driving the turbine 109a passes through the exhaust pipe 108, enters the exhaust gas purification device 110 made of a catalyst layer, etc., is purified by the exhaust gas purification device 110, and is then discharged from the exhaust gas pipe 111 into the atmosphere. .
On the other hand, the compressor 109 b driven coaxially to the turbine 109 a compresses the air 112, and the compressed air enters the gas mixer 114 through the air pipe 113.

As the fuel gas 11, for example, a low calorie gas having a low methane concentration such as coal mine methane is used, and the low calorie gas is stored in the fuel gas supply source 115.
Further, the fuel gas 11 reaches the gas amount adjusting valve 116A through the main chamber fuel gas tube 12A branched from the fuel gas supply tube 12, and the gas amount and the open / close period are adjusted by the gas amount adjusting valve 116A. The gas mixer 114 is entered.
The gas mixer 114 premixes the air 112 from the air pipe 113 and the low-calorie fuel gas 11 from the main chamber fuel gas pipe 12A to generate a premixed gas. The engine is supplied to the supply port 103 of the engine.
The premixed gas reaches the supply valve 104 via the supply port 103, and is supplied into the main combustion chamber 101 by opening the supply valve 104.

  The sub chamber base 117 is fixed to the cylinder head 105 from the upper surface by a base presser 118. A sub chamber 119 having a constant volume is formed in the sub chamber base 117. A spark plug 120 is fixed to the upper portion of the sub chamber 119, and the gas in the sub chamber 119 is ignited by the spark plug 120. Further, a joint 121 is screwed into the cap retainer 118, and one end of the joint 121 is connected to the sub chamber fuel gas pipe 12B separated from the fuel gas supply pipe 12, and the other end is opened to the sub chamber 119. Connected to the fuel passage 122. Reference numeral 116B denotes a gas amount adjusting valve for the fuel gas supplied to the sub chamber 119.

At the time of combustion, as described above, the low-calorie fuel gas 11 from the low-calorie gas supply source 115 passes through the fuel gas supply pipe 12 to the fuel passage 122 via the sub chamber fuel gas pipe 12B. Enters and is ejected from the fuel passage 122 into the sub chamber 119. At this time, a spark is discharged by the spark plug 120 at a predetermined time, and an ignition flame generated by the ignition combustion is ejected to the main combustion chamber 101 through the communication hole 123.
On the other hand, the low-calorie gas after branching through the main chamber fuel gas pipe 12A enters the gas mixer 114 after the gas amount and opening / closing period are adjusted by the gas amount adjusting valve 116A.

In the gas mixer 114, a premixed gas of low-calorie gas and air is generated as described above, and this premixed gas is introduced into the supply port 103 of the gas engine 100. The premixed gas reaches the air supply valve 104 via the air supply port 103 and is supplied into the main combustion chamber 101 by opening the air supply valve 104.
On the other hand, a spark discharge is generated by the spark plug 120, and the ignition flame generated by this ignition combustion is ejected to the premixed gas in the main combustion chamber 101 through the communication hole 123, and the gas in the main combustion chamber 101 is combusted. .
The exhaust gas 124 after combustion combusted in the main combustion chamber 101 passes through the exhaust port 106 and is sent to the turbine 109a of the exhaust turbocharger 109 through the exhaust pipe 108.

  In the present invention, the composition and the dust concentration of the fuel gas supplied to such a gas engine are analyzed and controlled to achieve an appropriate operation.

FIG. 1 is a schematic diagram of a gas engine system according to a first embodiment.
As shown in FIG. 1, a gas engine system 10A according to this embodiment includes a fuel gas supply pipe 12 that supplies a fuel gas 11 to a main combustion chamber 101 and a sub chamber 119 of the gas engine, and the fuel gas supply pipe 12. A laser analyzer 13 is provided for measuring the gas composition and the dust concentration of the fuel gas by irradiating the fuel gas 11 therein with a laser beam 14B.

  Further, in this embodiment, a first bypass pipe 33A branched from the branch portion 31 of the fuel gas pipe 12 and having the first filter 32 is provided, and the amount of dust is determined from the result of the dust concentration of the laser analyzer 13. And control means 21 for performing control to introduce the fuel gas 11 into the first bypass pipe 33A when the value exceeds the threshold value.

  The laser analyzer 13 includes a laser irradiation device 15 that oscillates a laser fundamental wave (YAG laser beam: 1064 nm) 14A, and a first wavelength-converted laser beam of a 532 nm YAG second harmonic that oscillates the laser fundamental wave 14A. A first wavelength converter 16A that converts the wavelength into 14B, a measurement region 18 that introduces a first wavelength-converted laser beam 14B of 532 nm, irradiates the fuel gas 11, and generates the first Raman scattered light 17A; And a laser light receiving means 19 for measuring the generated first Raman scattered light 17A, and the gas composition of the fuel gas 11 is changed to the peak signal of the Raman scattered light based on the measurement result of the first wavelength conversion laser light 14B having a wavelength of 532 nm. In addition to obtaining from the spectrum, the soot concentration in the fuel gas is obtained from the baseline excluding the peak signal spectrum.

  In the present invention, the gas composition component and the dust component of the fuel gas 11 are used by using a specific first wavelength conversion laser beam (second harmonic of YAG laser: 532 nm) 14B as the laser beam irradiated to the measurement region 18. At the same time.

  In general, the baseline is only noise information such as electrostatic noise and stray light. However, when the first wavelength conversion laser beam 14B of 532 nm is used, this baseline information includes Mie scattered light caused by dust. Because it is included, it is valuable as dust concentration information.

  Since Raman scattering is a minute light, electrostatic noise is suppressed in the Raman scattering measurement system. Furthermore, the wavelength range may be 500 nm or more, and preferably about 500 to 800 nm. In this wavelength range, no fluorescence is generated and components are detected in the baseline. The Mie scattered component can be removed by a spectroscope, but it is difficult to remove completely due to the difference in intensity from Raman scattered light, and it remains as a base. This is utilized in the present invention.

Further, although the wavelength of 532 nm is exemplified by 532 nm, which is the second harmonic of the fundamental wave of the YAG laser, the present invention is not limited thereto, and any laser light in the above wavelength region may be used.
In the present embodiment, the second harmonic is illustrated and described. However, the present invention is not limited to this, and various nonlinear optical phenomena (sum frequency generation and the like) may be used.

  In the present invention, 532 nm, which is the second harmonic of the YAG laser beam, is used as the wavelength. However, the present invention is not limited to this, and the laser beam is 400 nm or more, more preferably 500 nm or more. Is preferred. Since the Mie scattering intensity decreases as the wavelength becomes longer, it is preferable to use laser light in the range of 400 to 1,100 nm, more preferably in the range of 400 to 700 nm.

Here, in this embodiment, the laser light receiving means 19 for detecting the Raman scattered light includes a spectroscopic unit 19a for measuring the first Raman scattered light 17A generated by the irradiation of the first wavelength conversion laser light 14B and an ICCD (Intensified). (Charge Coupled Device) camera 19b.
Here, in FIG. 1, the symbol M is a reflection mirror that reflects the first wavelength conversion laser beam 14B, L is a condenser lens that collects the first wavelength conversion laser beam 14B, and 20 is a data processing means (CPU). Are respectively illustrated.

  Here, the laser fundamental wave 14A from the laser irradiating device 15 is converted into a first wavelength conversion laser of the second harmonic of the 532 nm YAG laser by converting the laser fundamental wave (YAG: 1064 nm) 14A to the first wavelength converter 16A. The wavelength is converted into light 14B, reflected to the measurement region 18 side via the reflection mirror M, condensed by a condenser lens L as a condensing means, and then sent into the measurement region 18, and into the measurement region 18. The first wavelength conversion laser beam 14 </ b> B is incident and irradiated to the fuel gas 11 passing through the measurement region 18.

Note that, for example, a cylindrical lens may be used to oscillate the sheet-like laser light by optical collimation so that the entire region of the fuel gas supply pipe 12 is irradiated with the laser gas when the fuel gas 11 is introduced.
In this case, it is preferable that the laser light receiving means 19 has a different phase so that the whole of the sheet irradiated can be measured.

Here, the first Raman scattered light 17A scattered in the measurement region 18 is split by the spectroscopic unit 19a via an optical group (not shown) such as a polarizer, a condensing lens, and a filter, for example, and the spectroscopic unit The intensity of light of each wavelength is measured by the ICCD camera 19b connected to 19a.
Measurement data from the ICCD camera 19b is sent to a data processing means (CPU) 20, where the measurement data is processed.
Further, the Mie scattered light caused by the dust generated at the same time is measured in the same manner, and the measurement data is processed.

FIG. 4 is a chart of the Raman scattered light measurement result of the fuel gas of the gas engine. As shown in FIG. 4, methane (CH ₄ ) is 75%, carbon dioxide (CO ₂ ) is 12%, nitrogen (N ₂ ) is 12%, moisture (H ₂ O) is 5%, and other fuel gas is 3%. %. The ratio is calculated from the chart. Here, in FIG. 4, the baseline excluding the peak signal spectrum is the concentration due to Mie scattered light caused by dust.

  FIG. 5 shows the case where dust is contained and the baseline is raised, and the area below this baseline is the dust concentration.

  In the present invention, the gas composition is obtained from the peak signal spectrum of the Raman scattered light by using the second wavelength converted first laser beam 14B of the second harmonic of the specific 532 nm YAG laser, and the baseline is obtained by removing the peak signal spectrum. Thus, the dust concentration can be obtained from the gas component, and the gas component and the dust concentration can be simultaneously measured by one measurement.

According to this embodiment, in the laser analyzer 13, when the data processing means 20 can determine the fuel calorie from the gas composition of the fuel gas 11 and determines that the dust concentration exceeds a predetermined threshold value. The control means 21 switches the flow path of the branching portion (for example, a damper) 31 to introduce the fuel gas 11 into the first bypass pipe 33A, and the filter interposed in the first bypass pipe 33 The dust is removed.
As the first filter 32, for example, a ceramic sintered filter having good dust removal efficiency can be used.

Thereby, even if the dust is transiently included in the fuel gas 11, it can be appropriately handled.
Further, for example, the foreign matter removing means such as the filter 32 can be used only when necessary, and the durability of the foreign matter removing means is improved.
As a result, the clean fuel gas 11 is stably introduced, and the gas amount adjusting valve as the fuel gas supply valve is not clogged with foreign matter, and the cleanliness of the sub chamber 119 is maintained and stable. Combustion can be ensured.

FIG. 2 is a schematic diagram of a gas engine system according to the second embodiment.
As shown in FIG. 2, the gas engine system 10B according to the present embodiment includes a laser irradiation device 15 that oscillates a laser fundamental wave (1064 nm) 14A, and the oscillated laser fundamental wave 14A that has a second harmonic of 532 nm. A first wavelength converter 16A that converts the wavelength of the first wavelength conversion laser beam 14B to a wavelength conversion laser beam 14B; a detour optical path that bypasses the laser fundamental wave (1064 nm) 14A to the downstream side of the first wavelength converter 16A; Second wavelength conversion for converting the wavelength of the combined laser beam 14C obtained by combining the laser fundamental wave 14A and the first harmonic laser beam 14B of 532 nm into the second wavelength converted laser beam 14D of the third harmonic (355 nm). A measurement region 18 for introducing a second wavelength-converted laser beam 14D having a wavelength of 355 nm and irradiating the fuel gas 11 to generate the second Raman scattered light 17B; And a laser light receiving means 19 for measuring the second Raman scattered light 17B. Based on the measurement result of the second wavelength conversion laser light 14D having a wavelength of 355 nm, the gas composition of the fuel 11 is determined from the peak signal spectrum of the Raman scattered light. In addition to the determination, the soot and hydrocarbon (HC) concentrations in the fuel gas 11 are determined from the baseline excluding the peak signal spectrum.
Here, M ₁ and M ₂ are reflection mirrors, and form a bypass optical path that bypasses the first wavelength converter 16A.

  In Example 2, the laser fundamental wave 14A of 1064 nm and the first wavelength conversion laser light 14B of 532 nm are combined to form a combined laser light 14C, and this combined laser light 14C is obtained by the second wavelength converter 16B. The second wavelength conversion laser beam 14D of 355 nm is used, and the second wavelength conversion laser beam 14D is used to cut the wavelength of 355 nm or less and detect it by the laser light receiving means 19, so that the gas composition and the dust concentration ( A combination of Mie scattered light) and HC (fluorescence) concentration can be measured.

  FIG. 6 is a chart showing the results. Here, in FIG. 6, the area below the baseline is a combination of the dust concentration (Mie scattered light) and the hydrocarbon (HC) concentration (fluorescence).

  In general, the baseline is only noise information such as electrostatic noise and stray light, but when the second wavelength conversion laser light 14D of 355 nm is used, the baseline information includes Mie scattered light caused by dust. Since it contains fluorescence caused by hydrocarbons (HC), it is valuable as dust concentration information and hydrocarbon concentration information.

  Since Raman scattering is a minute light, electrostatic noise is suppressed in the Raman scattering measurement system. Furthermore, the wavelength range may be 500 nm or less, and preferably about 250 to 400 nm. In this wavelength range, the hydrocarbon (HC) due to fluorescence and the dust component due to Mie scattered light are detected. The Mie scattered component can be removed by a spectroscope, but it is difficult to remove completely due to the difference in intensity from Raman scattered light, and it remains as a base. This is utilized in the present invention.

  In the present embodiment, the first bypass pipe 33 branched from the branch section 31 of the fuel gas pipe 12 and having the first filter 32, the branch pipe 34 is provided in the bypass pipe 33, and the activated carbon filter 35 is further provided. A second bypass pipe 33B is provided.

  According to this embodiment, in the laser analyzer 13, when the data processing means 20 can determine the fuel calorie from the gas composition of the fuel gas 11 and determines that the dust concentration exceeds a predetermined threshold value. The control means 21 switches the flow path of the branch portions (for example, dampers) 31 and 34 to introduce the fuel gas 11 into the second bypass pipe 33B and is interposed in the second bypass pipe 33B. The activated carbon filter 35 removes soot and hydrocarbons (HC).

  In addition, if an engine condition monitoring device that monitors the gas engine condition is applied, it is possible to automatically set (control) calories according to fluctuations in the inner cylinder temperature, rotation speed, inner cylinder pressure, etc., and soot and HC are transient. Even if it is introduced into the system, a robust gas engine system capable of quickly removing it can be provided.

  Thereby, the clean fuel gas 11 is introduced into the sub chamber 119, the cleanliness of the sub chamber 119 is maintained, and stable combustion can be ensured.

FIG. 3 is a schematic diagram of a gas component measuring apparatus according to the third embodiment.
As shown in FIG. 3, the gas component measuring apparatus 10C includes a laser irradiation device 15 that oscillates a laser fundamental wave (1064 nm) 11A, and a first wavelength conversion of the oscillated laser fundamental wave 14A to a second harmonic of 532 nm. A first wavelength converter 16A that converts the wavelength into laser light 14B, a bypass optical path that bypasses the laser fundamental wave (1064 nm) 14A to the downstream side of the first wavelength converter 16A, and a laser fundamental wave 14A of 1064 nm. And a second wavelength converter 16B that converts the wavelength of the combined laser beam 14C of the first wavelength conversion laser beam 14B of 532 nm into a second wavelength conversion laser beam 14D of the third harmonic (355 nm), and 532 nm The first wavelength conversion laser light 14B and the second wavelength conversion laser light 14D of 355 nm are introduced with a time delay, and the fuel gas 11 is irradiated to the first and second Raman. The first wavelength conversion laser beam 14B having a wavelength of 532 nm is provided with a measurement region 18 that generates the scattered light 17A and 17B, and a laser light receiving unit 19 that measures the generated first and second Raman scattered light 17A and 17B. From the measurement result, the gas composition of the fuel gas 11 is obtained from the peak signal spectrum of the Raman scattered light, and the soot concentration in the exhaust gas is obtained from the baseline excluding the peak signal spectrum.
At the same time, the gas composition of the fuel gas 11 is obtained from the peak signal spectrum of the Raman scattered light based on the measurement result of the second wavelength conversion laser light 14D having a wavelength of 355 nm, and the concentration of soot and hydrocarbon (HC) in the exhaust gas is determined. It is obtained from the baseline excluding the peak signal spectrum, and the dust concentration is estimated from the difference between the two. In FIG. 3, reference numerals M ₁ , M ₂ , M ₃ and M ₄ denote reflection mirrors, and L ₁ and L ₂ denote lenses.

Here, the process of estimating the dust concentration from the difference between the two will be described.
FIG. 7-1 is a calibration curve showing the relationship between Mie scattered light intensity and dust concentration at a wavelength of 532 nm. FIG. 7-2 is a calibration curve showing the relationship between Mie scattered light intensity and dust concentration at a wavelength of 355 nm.

Step 1) In Example 3, the configuration of Example 1 and Example 2 is combined. From the measurement value (for example, 1.8 A.U) based on the measurement result of the first wavelength conversion laser beam 14B having a wavelength of 532 nm. The soot concentration (1.0 mg / m ³ N) is obtained from the first calibration curve (FIG. 7-1).
Step 2) Next, from the measurement result of the second wavelength conversion laser light 14D having a wavelength of 355 nm, the Mie scattered light intensity (for example, 15 AU) is calculated from the dust concentration (1.0 mg / m ³ N) by the second Obtained from a calibration curve (Figure 7-2).
Step 3) Then, by dividing the Mie scattered light intensity (for example, 15 A.U) obtained in Step 2) from the actual measurement value with the second wavelength conversion laser beam 41D having a wavelength of 355 nm, hydrocarbon (HC) Determine the concentration of.

Here, hydrocarbon (HC) is an aggregate of hydrocarbons such as anthracene and naphthalene, and the combustion state can be estimated from the concentration tendency.
Furthermore, a calibration curve may be prepared in advance for specific HC (for example, anthracene or naphthalene), and an approximate concentration of anthracene or naphthalene may be obtained by applying the HC concentration to the calibration curve.

  Thus, stable combustion can be achieved by grasping the gas composition, dust, and hydrocarbons (HC) with a single device and taking measures based on the results.

10A to 10C Gas engine system 100 Gas engine 101 Main combustion chamber 119 Sub chamber 11 Fuel gas 12 Fuel gas supply pipe 13 Laser analyzer 14A Laser fundamental wave 14B First wavelength conversion laser beam 14C Combined laser beam 14D Second wavelength Converted laser light 15 Laser irradiation device 16A First wavelength converter 16B Second wavelength converter 17A First Raman scattered light 17B Second Raman scattered light 18 Measurement region 19 Laser light receiving means 21 Control means

Claims (7)

A fuel gas supply pipe for supplying fuel gas to a main combustion chamber and a sub chamber of the gas engine;
A laser analyzer that measures the gas composition and dust concentration of the fuel gas by irradiating the fuel gas in the fuel gas supply pipe with a laser beam;
A first bypass pipe branched into the fuel gas pipe and having a first filter;
A gas engine system comprising: control means for performing control for introducing fuel gas into the first bypass pipe when the amount of dust exceeds a threshold value as a result of the dust concentration of the laser analyzer . Oite to claim 1,
Having a second bypass pipe with a second filter;
Control for introducing the fuel gas into the second bypass pipe having the second filter when the hydrocarbon concentration is determined by the laser device and the hydrocarbon concentration exceeds the threshold value based on the result of the hydrocarbon concentration of the laser device. A gas engine system. In claim 1 or 2 ,
The laser analyzer is
A laser irradiation device for oscillating a laser fundamental wave;
A first wavelength converter for wavelength-converting the oscillated laser fundamental wave to a first wavelength-converted laser beam;
A measurement unit that introduces a wavelength-converted first wavelength-converted laser beam and irradiates the fuel gas to generate first Raman scattered light; and
A Raman scattered light detector for measuring the generated first Raman scattered light,
According to the measurement result of the first Raman scattered light, the gas composition of the fuel gas is obtained from the peak signal spectrum of the Raman scattered light, and the soot concentration in the fuel gas is obtained from the baseline excluding the peak signal spectrum. Gas engine system. In claim 2 ,
The laser analyzer is
A laser irradiation device that oscillates a laser fundamental wave; and
A first wavelength converter for wavelength-converting the oscillated laser fundamental wave to a first wavelength-converted laser beam;
A second wavelength converter that combines the laser fundamental wave and the first wavelength conversion laser light, and converts the wavelength of the combined laser light into a second wavelength conversion laser light;
A measurement region for introducing a second wavelength-converted laser beam and irradiating the fuel gas to generate a second Raman scattered light;
A Raman scattered light detector for measuring the generated second Raman scattered light,
From the measurement result of the second Raman scattered light, the gas composition of the fuel gas is obtained from the peak signal spectrum of the second Raman scattered light, and the concentrations of soot and hydrocarbons in the fuel exhaust gas are excluded from the peak signal spectrum. A gas engine system characterized by obtaining from a baseline. In claim 2 ,
The laser analyzer is
A laser irradiation device for oscillating a laser fundamental wave;
A first wavelength converter for wavelength-converting the oscillated laser fundamental wave to a first wavelength-converted laser beam;
A measurement region for introducing a first wavelength-converted laser beam and irradiating the fuel gas to generate first Raman scattered light;
A second wavelength converter that combines the laser fundamental wave and the first wavelength conversion laser light, and converts the wavelength of the combined laser light into a second wavelength conversion laser light;
A measurement region that introduces a second wavelength-converted laser beam and irradiates the exhaust gas to generate second Raman scattered light; and
A Raman scattered light detector for measuring the generated first or second Raman scattered light,
From the measurement result of the first Raman scattered light, the gas composition of the fuel gas is determined from the peak signal spectrum of the first Raman scattered light, and the soot concentration in the fuel gas is determined from the baseline excluding the peak signal spectrum, and,
Based on the measurement result of the second Raman scattered light, the gas composition of the exhaust gas is obtained from the peak signal spectrum of the second Raman scattered light, and the concentrations of soot and hydrocarbons in the fuel gas are obtained from the baseline. Gas engine system characterized by estimating dust concentration from In any one of Claim 3 thru | or 5 ,
The signal intensity (R ₀ ) of the Raman scattered light of the reference gas existing in the fuel gas is measured in advance,
Each time measurement is performed, the signal intensity (R ₁ ) of the Raman scattered light of the reference gas existing in the measurement region is measured,
The obtained R ₀ / R ₁ is set as a calibration constant (K), and the true signal intensity is obtained by multiplying each detected signal intensity (X ₁ ) of the peak signal spectrum by a calibration coefficient (K = R ₀ / R ₁ ). A gas engine system characterized by calculating a gas composition and a dust concentration (M ₂ ) from a true signal intensity. In any one of Claims 1 thru | or 6 ,
A gas engine system characterized in that a laser beam to be irradiated is in a sheet form.

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