JP2011021616A - Gas supply device of gas engine and the gas engine equipped with the gas supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce energy loss for fuel gas compression by eliminating the need for a gas compressor dedicated for fuel gas compression. <P>SOLUTION: In a gas engine, an exhaust turbocharger includes a fuel gas supercharger equipped with a fuel gas compressor for compressing the fuel gas and a first turbine for driving the fuel gas compressor by energy of exhaust gas, and an air supercharger equipped with an air compressor for compressing air and a second turbine for driving the air compressor by the energy of the exhaust gas. The fuel gas compressed by the fuel gas supercharger and the air compressed by the air supercharger are mixed, and the mixture is supplied to respective cylinders. The first turbine of the fuel gas supercharger and the second turbine of the air supercharger are connected in series to an exhaust passage. Exhaust gas generated after driving either the first turbine or the second turbine is used for driving the other turbine, or the first turbine and the second turbine are unified. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is particularly suitable for a gas engine using a low calorie gas (a gas having a low calorific value) as a fuel gas, and includes an exhaust turbocharger, which mixes fuel gas and air supplied through a fuel gas passage. A gas supply device for a gas engine that supplies the air-fuel mixture into a cylinder and ignites and burns the gas mixture, and the gas supply device for the gas engine configured to compress fuel gas and air by separate superchargers, and The present invention relates to a gas engine provided with the gas supply device.

In a lean combustion gas engine, fuel gas and air are mixed while controlling to a required air-fuel ratio, and this mixed gas is supplied to the combustion chamber of the engine through a supply pipe equipped with a mixed gas flow rate adjusting means such as a throttle valve. is doing.
Among such lean combustion gas engines, in a gas engine equipped with an exhaust turbocharger (hereinafter referred to as a supercharger), the following two types of fuel gas supply methods are used.
(1) The fuel gas pressurized to a pressure higher than the supercharging air pressure by the gas compressor is injected into the supply branch pipe of each cylinder immediately before each cylinder.
(2) The fuel gas is mixed with the supercharger inlet air and the air-fuel mixture is supplied to the supercharger. The air-fuel mixture is compressed by the supercharger and supplied to the engine.

Further, as a technique combining the means (1) and the means (2), a technique disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2001-132550) is provided.
In this technique, the fuel gas pressurized by the gas compressor is supplied to the cylinder inlet or the cylinder of the supply passage, and the fuel gas before being pressurized by the gas compressor is supplied to the air passage upstream of the supercharger. Supply and mix with air, compress this mixture with the compressor of the supercharger and supply it to the cylinder inlet or cylinder of the supply passage, and further supply the fuel gas directly to the cylinder side supply passage And the supply of fuel gas to the air passage upstream of the supercharger can be switched by a switching valve.

JP 2001-132550 A

However, the conventional technique provided in Patent Document 1 has the following problems.
That is, in the direct fuel gas supply system that supplies the fuel gas pressurized by the gas compressor to the cylinder inlet of the supply passage or into the cylinder, it is necessary to compress the fuel gas to a pressure higher than the supercharging air pressure. In the direct fuel gas supply system of the technology, a dedicated gas compressor is installed, so when using low calorie gas (low calorific gas) such as coal mine methane gas as fuel gas, low pressure and large flow rate A large and large capacity gas compressor is required to compress the gas.
On the other hand, in the prior art, the fuel gas before being pressurized by the gas compressor is supplied to the air passage on the upstream side of the supercharger and mixed with air, and the air-fuel mixture is compressed by the compressor of the supercharger and supplied. In the supercharger-compressed mixed gas supply system that supplies to the air passage side, the supercharger pressurizes the mixed gas, which is highly flammable by mixing fuel gas and air, to a high temperature and high pressure with the supercharger. It contains the danger of a gas mixture exploding at the exit.

  Therefore, in view of the problems of the prior art, the present invention eliminates the need for a dedicated gas compressor for compressing fuel gas, reduces energy loss for fuel gas compression, simplifies the structure, and reduces low calorie gas (low heat generation). It is an object of the present invention to provide a gas supply device for a gas engine that makes it possible to easily use an amount of gas) fuel and further eliminates the possibility of explosion of a mixed gas at a supercharger outlet.

The present invention achieves such an object, and includes an exhaust turbocharger driven by exhaust gas from an engine, mixes fuel gas and air supplied through a fuel gas passage, and mixes the mixture into each cylinder. A gas engine that is supplied to the inside and ignited and combusted, wherein the exhaust turbocharger includes a fuel gas compressor that compresses the fuel gas, and a fuel gas that includes a first turbine that drives the fuel gas compressor by the energy of the exhaust gas And a supercharger for air having a second turbine for driving the air compressor by the energy of the exhaust gas and an air compressor for compressing the air, and compressed by the supercharger for fuel gas The compressed fuel gas and the air compressed by the air supercharger are mixed and supplied to each cylinder. As a child to the subject matter,
According to a first aspect of the invention, in addition to the gist, a first turbine of the fuel gas supercharger and a second turbine of the air supercharger are connected in series to an exhaust passage, and the first turbine or the second turbine It is characterized in that the other turbine is driven by the exhaust gas after driving any one of the turbines.

  According to a second aspect of the present invention, the first turbine and the second turbine are united, and either one of the united turbine and a coupling shaft of a fuel gas compressor or a coupling shaft of an air compressor has the above-described configuration. And a transmission device that shifts and transmits the turbine rotational speed to a fuel gas compressor or an air compressor.

  According to this invention, the exhaust turbocharger includes a fuel gas compressor that compresses fuel gas, a fuel gas supercharger that includes a first turbine that drives the fuel gas compressor, an air compressor that compresses air, and The turbocharger is constituted by two superchargers including an air supercharger provided with a second turbine for driving the air compressor, and is compressed by the fuel gas compressed by the fuel gas supercharger and the air supercharger. Since the air is supplied to the inlet of each cylinder, the fuel gas is compressed using the energy of the exhaust gas, as in the prior art provided in Patent Document 1 above. Even when using low-calorie gas such as coal mine methane gas by controlling the capacity of the fuel gas supercharger, a dedicated gas compressor for compressing fuel gas is no longer necessary. The gas pressure can be easily obtained, thus, without requiring a dedicated gas compressor for compressing fuel gas, it is possible to stabilize operation at low calorie gas such as coal mine methane gas.

  Therefore, according to this invention, the fuel gas is compressed using the energy of the exhaust gas, so that the energy loss for the compression of the fuel gas can be reduced, and the fuel gas is compressed using the function of the exhaust turbocharger. By doing so, the structure is simpler and less costly than when a dedicated gas compressor for compressing fuel gas is provided.

  Further, according to the present invention, only the fuel gas is compressed by the fuel gas compressor of the fuel gas supercharger, and only the air is compressed by the air compressor of the air supercharger. Since the mixture is generated in front of the inlet of each cylinder to generate the mixture and the mixture is supplied into each cylinder, the fuel gas compressor compresses only the fuel gas. Compared with the one that compresses the mixture of fuel gas and air, there is almost no risk of the fuel gas exploding at the outlet of the supercharger, and the engine can be operated safely.

  In particular, in the first invention, the first turbine of the fuel gas supercharger and the second turbine of the air supercharger are connected in series to an exhaust passage, and either the first turbine or the second turbine is connected. Since the other turbine is driven by the exhaust gas after driving the turbine of the turbine, the fuel gas turbocharger turbine and the air turbocharger turbine are connected in series to the exhaust passage. By doing so, the exhaust energy of the engine can be used efficiently.

According to the second invention, the fuel gas compressor and the air compressor are driven by one exhaust turbine, and the transmission is connected to the connecting shaft between the exhaust turbine and the fuel gas compressor or the connecting shaft between the exhaust turbine and the air compressor. The flow rate ratio between the fuel gas amount from the fuel gas compressor and the air amount from the air compressor and the pressure ratio between the fuel gas pressure from the fuel gas compressor and the air pressure from the air compressor are Can be adjusted to an appropriate value.
In addition, since the fuel gas compressor and the air compressor are driven by one exhaust turbine, the number of exhaust turbines can be minimized, the number of devices is reduced, and the structure is simplified.

  In this invention, preferably, an exhaust bypass passage that bypasses the exhaust turbine from the exhaust passage at the inlet of the exhaust turbine and is released to the exhaust outlet side is provided, and an exhaust bypass valve that opens and closes the exhaust bypass passage is provided, A controller is provided for controlling the opening degree of the exhaust bypass valve so that the air-fuel mixture amount to the engine becomes the target air-fuel mixture amount.

With this configuration, the opening degree of the exhaust bypass valve is controlled according to the operating conditions of the engine in the gas engine having the exhaust gas turbocharger that drives the fuel gas compressor and the air compressor with one exhaust turbine. To adjust the amount of exhaust gas supplied to the fuel gas supercharger and the air supercharger to an exhaust gas amount that conforms to the operating conditions, and to change the amount of air-fuel mixture to the engine for each operating condition And the engine can be operated with the excess air ratio maintained substantially constant.
The gas supply apparatus having the above configuration can be applied to all gas engines.

According to the present invention, an exhaust turbocharger includes a fuel gas compressor for fuel gas compression and a fuel gas turbocharger having a first turbine for driving the fuel gas compressor, an air compressor for air compression, and the air compressor. Each of the fuel gas compressed by the fuel gas supercharger and the air compressed by the air supercharger. By being configured to supply to the inlet of the cylinder, the fuel gas can be compressed using the energy of the exhaust gas, and there is no need for a dedicated gas compressor for fuel gas compression as in the prior art, Even when using low-calorie gas such as coal mine methane gas, the required gas pressure can be easily obtained by controlling the capacity of the supercharger for fuel gas. Without requiring the scan compressor, it is possible to stabilize operation at low calorie gas such as coal mine methane gas.
Therefore, according to the present invention, by compressing the fuel gas using the energy of the exhaust gas, energy loss for the compression of the fuel gas can be reduced, and the function of the exhaust turbocharger can be used to reduce the fuel gas. Compressing makes the structure simpler and less expensive than providing a dedicated gas compressor for compressing fuel gas.

  Further, according to the present invention, only the fuel gas is compressed by the fuel gas compressor of the fuel gas supercharger, and only the air is compressed by the air compressor of the air supercharger. Since the fuel gas compressor compresses only the fuel gas by mixing in front of the inlet of each cylinder to generate the air-fuel mixture and supplying it into each cylinder, the fuel-air and air-fuel mixture is There is almost no risk of the fuel gas exploding at the outlet of the turbocharger, such as the one that compresses, and the engine can be operated safely.

According to the second aspect of the invention, the fuel gas compressor for compressing the fuel gas and the air compressor for compressing the air are driven to rotate by a single exhaust turbine, and the connecting shaft of the exhaust turbine and the fuel gas compressor or By providing a structure in which one or both of the connecting shafts of the exhaust turbine and the air compressor are provided with a transmission, a flow rate ratio between the fuel gas amount from the fuel gas compressor and the air amount of the air compressor, and The pressure ratio between the fuel gas pressure from the fuel gas compressor and the air pressure from the air compressor can be adjusted to an appropriate value depending on the engine operating conditions.
In addition, since the fuel gas compressor and the air compressor are driven by one exhaust turbine, the number of exhaust turbines can be minimized, the number of devices is reduced, and the structure is simplified.

1 is an overall configuration diagram of a gas supply device for a gas engine according to the present invention. It is a systematic diagram of the supercharger for fuel gas and the supercharger for air which shows the 1st reference example of this invention. FIG. 3 is a diagram corresponding to FIG. 2 illustrating a second reference example of the present invention. FIG. 3 is a view corresponding to FIG. 2 showing a first embodiment of the present invention. FIG. 9 is a diagram corresponding to FIG. 2 illustrating a third reference example of the present invention. FIG. 3 is a view corresponding to FIG. 2 showing a second embodiment of the present invention. FIG. 9 is a view corresponding to FIG. 2 showing a seventh embodiment of the present invention. FIG. 9 is a diagram corresponding to FIG. 2 illustrating a fourth reference example of the present invention.

  Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

FIG. 1 is an overall configuration diagram of a gas supply device for a gas engine according to the present invention. In FIG. 1, 1 is an engine (gas engine), 4 is a cylinder head of the engine 1, 130 is a generator directly driven by the engine 1, and 14 is a flywheel. 3 is an air supply branch pipe connected to the air supply inlet of each cylinder head 4, and 2 is an air supply outlet of an air compressor 9 of the air supercharger 51 described later and each of the air supply branch pipes 3. An air supply pipe 90 is an air supply cooler for cooling the air supplied through the air supply pipe 2.
Reference numeral 5 denotes an exhaust pipe connected to the exhaust outlet of each cylinder head, and 6 denotes an exhaust collecting pipe connected to each exhaust pipe 5.

21 is a fuel gas inlet pipe. 50 is a fuel gas supercharger, and a fuel gas compressor 7 that compresses the fuel gas from the fuel gas inlet pipe 21 and a first turbine that directly drives the fuel gas compressor 7 by the energy of the exhaust gas from the engine 1. The first turbine 8 is driven by exhaust gas introduced from the exhaust collecting pipe 6 through the first turbine inlet passage 61.
An air supercharger 51 includes an air compressor 9 that compresses air taken in from the atmosphere, and a second turbine 10 that directly drives the air compressor 9 by the energy of exhaust gas from the engine 1. The two turbines 10 are driven by exhaust gas introduced from the exhaust collecting pipe 6 through the second turbine inlet passage 62.

Reference numeral 30 denotes an exhaust gas flow rate adjusting valve that is provided in the first turbine inlet passage 61 and adjusts the exhaust gas flow rate to the first turbine 8. The exhaust gas flow rate adjusting valve 30 can be provided in the second turbine inlet passage 62, or can be provided in both the first turbine inlet passage 61 and the second turbine inlet passage 62.
Reference numeral 12 denotes an exhaust bypass passage, which is branched from a portion of the exhaust collecting pipe 6 near the inlet of the first turbine inlet passage 61 and the second turbine inlet passage 62 to bypass the first turbine 8 and the second turbine 10. It is connected to a discharge pipe (not shown). An exhaust bypass valve 13 changes the passage area of the exhaust bypass passage 12.

  Reference numeral 210 denotes a fuel gas pipe connected to the gas outlet of the fuel gas compressor 7. The fuel gas pipe 210 is branched for each cylinder on the way and becomes a gas supply branch pipe 213 which is connected to each supply branch pipe 3. ing. 19 is a supercharger side gas amount adjusting valve installed in the fuel gas pipe 210 to control the passage area of the fuel gas pipe 210, that is, a fuel gas flow rate, and 20 is installed in each gas supply branch pipe 213. This is a cylinder side gas amount adjusting valve for controlling the passage area of the gas supply branch pipe 213, that is, the fuel gas flow rate.

Reference numeral 15 denotes an engine speed sensor for detecting the engine speed, 013 denotes a load detector for detecting the load of the generator 13, that is, an engine load, 17 denotes an air supply pressure sensor for detecting the air supply pressure in the air supply pipe 2, and 18 This is a supply air temperature sensor for detecting a supply air temperature.
Reference numeral 24 is a rotation speed controller, 23 is an air-fuel ratio controller, 22 is a gas amount controller, and the detected value of the engine speed from the rotation speed sensor 15 is input to the rotation speed controller 24 and the gas amount controller 22 to detect the load. The detected value of the engine load from the device 013 is input to the air-fuel ratio controller 23, the detected value of the supply air pressure from the supply air pressure sensor 17 is input to the air-fuel ratio controller 23 and the gas amount controller 22, and the supply air temperature The detected value of the supply air temperature from the sensor 18 is input to the air-fuel ratio controller 23 and the gas amount controller 22.

The rotational speed controller 24 is a normal electronic governor and calculates the fuel gas amount to each cylinder based on the detected value of the engine rotational speed from the rotational speed sensor 15, and the cylinder side gas amount adjusting valve based on the calculated value. The opening degree of 20 is controlled.
The air-fuel ratio controller 23 is based on the detected value of the engine load from the load detector 013, the detected value of the supplied air pressure from the supplied air pressure sensor 17, and the detected value of the supplied air temperature from the supplied air temperature sensor 18. The opening degree of the exhaust bypass valve 12 and the opening degree of the exhaust gas flow rate adjustment valve 30 are controlled by means to be described later.
The gas amount controller 22 converts the detected value of the engine speed from the rotational speed sensor 15, the detected value of the supplied air pressure from the supplied air pressure sensor 17, and the detected value of the supplied air temperature from the supplied air temperature sensor 18. Based on this, the opening degree of the supercharger side gas amount adjusting valve 19 is controlled by means to be described later.

During the operation of the gas engine, the air compressed by the air compressor 9 of the air supercharger 51 is cooled and cooled by the air cooler 90, and then passes through the air supply pipe 2 in the air supply branch pipe 3 of each cylinder. Flow into.
On the other hand, the fuel gas from the gas supply pipe 21 is compressed by the fuel gas compressor 7 of the fuel gas supercharger 50, passes through the fuel gas pipe 210 and the supercharger side gas amount adjusting valve 19, and is supplied to each cylinder. It branches into the gas supply branch pipe 213, enters each of the supply branch pipes 3, is mixed into the air from the air compressor 9 in the supply branch pipe 3, and this mixture is sent into each cylinder.

The exhaust gas from each cylinder of the engine 1 passes through the exhaust pipe 5 and is merged in the exhaust collecting pipe 6, and then is split into the first turbine inlet passage 61 and the second turbine inlet passage 62, and the first turbine Exhaust gas passing through the inlet passage 61 drives the first turbine 8 of the fuel gas supercharger 50, and exhaust gas passing through the second turbine inlet passage 62 passes through the second turbine of the air supercharger 51. 10 is driven and discharged to the outside through a discharge pipe (not shown).
When the exhaust bypass valve 13 is opened by a control operation signal as will be described later from the air-fuel ratio controller 23, a part of the exhaust gas in the exhaust collecting pipe 6 passes through the exhaust bypass passage 12 and is not shown. Discharged into the tube.

  In the gas amount controller 22, the detected value of the engine speed from the rotational speed sensor 15, the detected value of the supplied air pressure from the supplied air pressure sensor 17, and the detected value of the supplied air temperature from the supplied air temperature sensor 18. Based on the above, the fuel gas amount that matches the detected values of the engine air supply pressure, the air supply temperature, and the fuel gas flow rate is calculated, and the supercharger side gas amount adjusting valve 19 is set to an opening corresponding to the fuel gas amount. To control the opening degree.

In the air-fuel ratio controller 23, the engine load detection value from the load detector 013, the supply air pressure detection value from the supply air pressure sensor 17, and the supply air temperature detection value from the supply air temperature sensor 18. Based on the engine load, the supply air pressure, and the supply air temperature, the opening degree of the exhaust bypass valve 13 is calculated, and the opening degree of the exhaust bypass valve 13 is controlled to the calculated opening degree.
In the air-fuel ratio controller 23, based on the detection value of the engine load, the detection value of the supply air pressure, and the detection value of the supply air temperature, the air-fuel ratio suitable for these detection values and the air-fuel ratio are set. The flow rate ratio between the exhaust flow rate of the first turbine 8 of the fuel gas supercharger 50 and the exhaust flow rate of the second turbine 10 of the air supercharger 51 is calculated, and the exhaust gas is adjusted so that this flow rate ratio is obtained. The opening degree of the gas flow rate adjusting valve 30 is controlled.

  According to the second reference example, the exhaust turbocharger includes a fuel gas supercharger 50 including a fuel gas compressor 7 that compresses fuel gas, and a first turbine 8 that drives the fuel gas compressor 7; The turbocharger is composed of two systems: an air compressor 9 that compresses air and an air supercharger 51 that includes a second turbine 10 that drives the air compressor 9, and is compressed by a fuel gas supercharger 50. Since the fuel gas and the air compressed by the air supercharger 51 are supplied to the inlet of each cylinder, the fuel gas is compressed using the energy of the exhaust gas of the engine 1. Thus, a dedicated gas compressor for compressing the fuel gas as in the prior art becomes unnecessary, and even when a low calorie gas such as coal mine methane gas is used, the capacity of the fuel gas supercharger 50 is controlled. By, it is possible to easily obtain the required gas pressure. Thereby, stable operation with low-calorie gas such as coal mine methane gas becomes possible without requiring a dedicated gas compressor for compressing the fuel gas.

  Therefore, according to the second reference example, since the fuel gas is compressed using the energy of the exhaust gas, the energy loss for the compression of the fuel gas can be reduced, and the function of the exhaust turbocharger is used to reduce the fuel. By compressing the gas, the structure is simplified and the cost is lower than when a dedicated gas compressor for compressing the fuel gas is provided.

Further, according to the second reference example, only the fuel gas is compressed by the fuel gas compressor 7 of the fuel gas supercharger 50, and only the air is compressed by the air compressor 9 of the air supercharger 51. Since the fuel gas and the compressed air are mixed before the entrance of each cylinder to generate an air-fuel mixture and the air-fuel mixture is supplied into each cylinder, the fuel gas compressor 7 compresses only the fuel gas. Therefore, the risk of the fuel gas exploding at the outlet of the supercharger is almost eliminated as compared with the conventional technology that compresses the mixture of fuel gas and air, and the engine can be operated safely.
[Reference Example 1]

FIG. 2 is a system diagram of a fuel gas supercharger and an air supercharger showing a first reference example of the present invention.
As in the second reference example of FIG. 1, the first reference example includes a first turbine side exhaust passage 61 that connects the exhaust passage from the engine to the first turbine 8 inlet of the fuel gas supercharger 50, And branching to a second turbine side exhaust passage 62 connected to the inlet of the second turbine 10 of the air supercharger 51, and the passage area of the first turbine side exhaust passage 61 and the second turbine side exhaust passage 62. The passage areas are configured to have different passage areas adapted to the capacities of the fuel gas supercharger 50 and the air supercharger 51.
According to the first reference example, a flow rate difference is provided between the exhaust gas amount of the fuel gas supercharger 50 to the first turbine 8 and the exhaust gas amount of the second turbine 10 of the air supercharger 51. The capacities of the fuel gas supercharger 50 and the air supercharger 51 can be set to capacities adapted to the required fuel gas amount and the required air amount.
The other structure is the same as that of the said FIG. 1, and the same member is shown with the same code | symbol.
[Reference Example 2]

FIG. 3 is a diagram corresponding to FIG. 2 showing a second reference example of the present invention.
In the second reference example, as shown in FIG. 1 according to the second reference example, the first turbine side exhaust passage 61 connected to the inlet of the first turbine 8 of the fuel gas supercharger 50, The exhaust gas flow rate adjustment valve 30 is provided in the second turbine side exhaust passage 62 connected to the second turbine 10 inlet of the air supercharger 51 (the exhaust gas flow rate adjustment valve 30 is provided in the second turbine inlet passage 62. And can be provided in both the first turbine inlet passage 61 and the second turbine inlet passage 62). In the air-fuel ratio controller 23, the detected value of the engine load, the detected value of the supply air pressure, And the air-fuel ratio that matches the detected value of the supply air temperature, and the exhaust flow rate of the first turbine 8 of the fuel gas supercharger 50 and the second turbine 10 of the air supercharger 51 so as to achieve this air-fuel ratio. Flow with exhaust flow And calculating the ratio, and controls the opening degree so that the flow ratio by the air-fuel ratio controller 23.
According to the second reference example, by controlling the opening degree of the exhaust gas flow rate adjustment valve 30, the amount of exhaust gas to the first turbine 8 of the fuel gas supercharger 50 and the air supercharger 51. The flow rate ratio (flow rate ratio) of the exhaust gas amount of the second turbine 10 can be freely changed depending on the operating conditions of the gas engine such as the engine load, the supply air pressure, the supply air temperature, etc. And the required air volume is always obtained.
The other structure is the same as that of FIG. 1, and the same member is shown with the same code | symbol.
[Example 1]

FIG. 4 is a view corresponding to FIG. 2 showing the first embodiment of the present invention.
In the first embodiment, the first turbine 8 of the fuel gas supercharger 50 and the second turbine 10 of the air supercharger 51 are connected in series in the exhaust passage, and the first turbine 8 or the second turbine 10 is connected in series. The other turbine is driven by the exhaust gas after driving one of the two turbines 10.
According to the first embodiment, by arranging the first turbine 8 for the fuel gas supercharger 50 and the second turbine 10 for the air supercharger 51 connected in series to the exhaust passage, The engine exhaust energy can be used efficiently.
The other structure is the same as that of the said FIG. 1, and the same member is shown with the same code | symbol.
[Reference Example 3]

FIG. 5 is a diagram corresponding to FIG. 2 showing a third reference example of the present invention.
In the third reference example, as also shown in FIG. 1 according to the second reference example, the first turbine 8 inlet of the fuel gas supercharger 50 and the second turbine 10 of the air supercharger 51 are used. An exhaust bypass passage 12 that bypasses the first turbine 8 and the second turbine 10 from the exhaust passage connected to the inlet and is released to the exhaust outlet side is provided.
The air-fuel ratio controller 23 controls the exhaust bypass valve 13 so that the air-fuel ratio becomes suitable for the engine operating conditions such as the engine load detection value, the supply air pressure detection value, and the supply air temperature detection value. The opening degree is calculated, and the opening degree of the exhaust bypass valve 13 is controlled to the calculated opening degree.
According to the third reference example, the amount of exhaust gas supplied to the fuel gas supercharger 50 and the air supercharger 51 is controlled by controlling the opening of the exhaust bypass valve 13 according to the engine operating conditions. By adjusting the exhaust gas amount to match the operating conditions, the air-fuel mixture amount to the engine can be controlled to the required air-fuel mixture amount for each operating condition, and the engine can be operated with the air excess ratio kept substantially constant. .
The other structure is the same as that of FIG. 1, and the same member is shown with the same code | symbol.
[Example 2]

FIG. 6 is a view corresponding to FIG. 2 showing a second embodiment of the present invention.
In the second embodiment, a fuel gas compressor 7 for compressing fuel gas, an air compressor 9 for compressing air, and the fuel gas compressor 7 and the air compressor 9 are connected to the fuel gas compressor 7 and the air compressor 9. The exhaust gas turbine 8a is driven to rotate, and the rotation speed of the exhaust turbine 8a is shifted (increased or decelerated) to the connecting shaft 310 of the exhaust turbine 8a and the fuel gas compressor 7 to thereby rotate the fuel gas compressor 7 A transmission 31 is provided for transmission to the vehicle. The transmission 31 may be provided on the connecting shaft 311 between the exhaust turbine 8a and the air compressor 9, or may be provided on both the connecting shaft 310 and the connecting shaft 311.

According to the second embodiment, the fuel gas compressor 7 and the air compressor 9 are driven by one exhaust turbine 8a, and the connecting shaft 310 between the exhaust turbine 8a and the fuel gas compressor 7 or the exhaust turbine 8a and the air compressor is driven. 9 is connected to the connecting shaft 311 and the flow rate ratio between the fuel gas amount from the fuel gas compressor 7 and the air amount from the air compressor 9 and the fuel gas pressure from the fuel gas compressor 7. The pressure ratio with the air pressure from the air compressor can be adjusted to an appropriate value according to the engine operating conditions.
Further, since the fuel gas compressor 7 and the air compressor 9 are driven by a single exhaust turbine 8a, the number of exhaust turbines 8a is minimized, and the number of devices is small and the structure is simplified.
The other structure is the same as that of the said FIG. 1, and the same member is shown with the same code | symbol.
[Example 7]

FIG. 7 is a view corresponding to FIG. 2 showing a seventh embodiment of the present invention.
In the seventh embodiment, in addition to the second embodiment, an exhaust bypass passage 12 that bypasses the exhaust turbine 8a from the exhaust passage at the inlet of the exhaust turbine 8a and is released to the exhaust outlet side is provided. An exhaust bypass valve 13 for opening and closing the bypass passage 12 is provided.
The air-fuel ratio controller 23 controls the exhaust bypass valve 13 so that the air-fuel ratio becomes suitable for the engine operating conditions such as the engine load detection value, the supply air pressure detection value, and the supply air temperature detection value. The opening degree is calculated, and the opening degree of the exhaust bypass valve 13 is controlled to the calculated opening degree.

According to the seventh embodiment, in the gas engine provided with the exhaust gas turbocharger that drives the fuel gas compressor 7 and the air compressor 9 with a single exhaust turbine 8a, the exhaust bypass valve 13 is controlled according to the engine operating conditions. By controlling the opening degree, the amount of exhaust gas supplied to the fuel gas supercharger 50 and the air supercharger 51 (see FIG. 1) is adjusted to the amount of exhaust gas suitable for the operating conditions, and is supplied to the engine. Therefore, the engine can be operated with the excess air ratio maintained substantially constant.
The other structure is the same as that of the said FIG. 1, and the same member is shown with the same code | symbol.
[Example 8]

FIG. 8 is a diagram corresponding to FIG. 2 showing a fourth reference example of the present invention.
In the fourth reference example, as shown in FIG. 1 according to the second reference example, the gas supply branch pipe for each cylinder is passed from the fuel gas compressor 7 of the fuel gas supercharger 50 through the fuel gas pipe 210. A cylinder side fuel gas amount adjustment that adjusts the flow rate of fuel gas to each cylinder upstream of the merging portion with the supply branch pipe 3 of the fuel gas passage branched from the 213II and connected to the combustion chamber 36 of each cylinder A valve 20 is provided, and the opening degree of the cylinder side fuel gas amount adjusting valve 20 is controlled by the rotation speed controller 24. 35 is a piston.
According to the fourth reference example, by adjusting the fuel gas flow rate for each cylinder by the cylinder-side fuel gas amount adjusting valve 20 provided in the fuel gas passage of each cylinder, the exhaust temperature and the air-fuel ratio vary among the cylinders. Can be reduced.
The other structure is the same as that of the said FIG. 1, and the same member is shown with the same code | symbol.

  According to the present invention, a dedicated gas compressor for compressing fuel gas is not required, energy loss for fuel gas compression can be reduced, the structure is simplified, and low calorie gas (low calorific gas) fuel is provided. Therefore, it is possible to provide a gas engine in which there is no possibility of explosion of the mixed gas at the supercharger outlet.

1 Engine (gas engine)
2 Supply Pipe 3 Supply Air Branch Pipe 6 Exhaust Collecting Pipe 7 Fuel Gas Compressor 8 First Turbine 9 Air Compressor 10 Second Turbine 7a Exhaust Turbine 12 Exhaust Bypass Path 13 Exhaust Bypass Valve 013 Load Detector 15 Rotation Speed Sensor 17 Supply Air Pressure Sensor 18 Supply air temperature sensor 19 Supercharger side gas amount adjusting valve 20 Cylinder side gas amount adjusting valve 21 Fuel gas inlet pipe 22 Gas amount controller 23 Air-fuel ratio controller 24 Speed controller 31 Transmission device 30 Exhaust gas flow rate adjusting valve 50 Fuel Supercharger for gas 51 Supercharger for air 61 First turbine inlet passage 62 Second turbine inlet passage 210 Fuel gas pipe 213 Gas supply branch pipe

Claims (4)

In a gas engine having an exhaust turbocharger driven by exhaust gas from an engine, mixing fuel gas and air supplied through a fuel gas passage, and supplying the mixture into each cylinder for ignition combustion A turbocharger for fuel gas, a supercharger for fuel gas comprising a fuel gas compressor for compressing the fuel gas, and a first turbine for driving the fuel gas compressor by the energy of the exhaust gas; and the air for compressing the air A fuel gas compressed by the fuel gas supercharger, and the air turbocharger, comprising: an air compressor; and a second turbocharger that drives the air compressor by the energy of the exhaust gas. Configured to mix and supply the compressed air at each cylinder,
After the first turbine of the fuel gas supercharger and the second turbine of the air supercharger are connected in series to the exhaust passage, after driving either the first turbine or the second turbine A gas supply apparatus for a gas engine, wherein the other turbine is driven by exhaust gas. In a gas engine having an exhaust turbocharger driven by exhaust gas from an engine, mixing fuel gas and air supplied through a fuel gas passage, and supplying the mixture into each cylinder for ignition combustion A turbocharger for fuel gas, a supercharger for fuel gas comprising a fuel gas compressor for compressing the fuel gas, and a first turbine for driving the fuel gas compressor by the energy of the exhaust gas; and the air for compressing the air A fuel gas compressed by the fuel gas supercharger, and the air turbocharger, comprising: an air compressor; and a second turbocharger that drives the air compressor by the energy of the exhaust gas. Configured to mix and supply the compressed air at each cylinder,
The first turbine and the second turbine are united, and the fuel gas compressor or the air compressor is connected to either one of the united turbine and the coupling shaft of the fuel gas compressor or the coupling shaft of the air compressor. A gas supply device for a gas engine, further comprising a transmission for shifting and transmitting the turbine rotational speed.   An exhaust bypass passage that bypasses the exhaust turbine from the exhaust passage at the inlet of the exhaust turbine and is released to the exhaust outlet side is provided, and an exhaust bypass valve that opens and closes the exhaust bypass passage is provided. The gas supply device for a gas engine according to claim 2, further comprising a controller for controlling the opening degree of the exhaust bypass valve so as to achieve a target air-fuel mixture amount.   A gas engine comprising the gas supply device according to any one of claims 1 to 3.

Images