JP2020133517A - Engine system - Google Patents

Abstract

To provide, in a configuration in which a modified gas from a modification cylinder is guided to a normal cylinder, a further improvement in efficiency of an engine system and expansion of output upper limit (expansion of torque upper limit) while satisfying a constraint of fuel supply amount and the supply amount of combustion air based on a stroke volume of a normal cylinder or a modification cylinder.SOLUTION: The present invention is configured such that a total stroke volume which is a sum of the stroke volumes of all normal cylinders 40a, 40b, 40c into which the modified gas is guided is larger than a total stroke volume which is a sum of the stroke volumes of all modification cylinders 40d. Based on the stroke volume ratio in which a total stroke volume of all normal cylinders 40a, 40b, 40c into which the modified gas K is guided is divided by a total stroke volume of the modification cylinder 40d, the stroke number ratio which is the value in which the stroke number of the normal cylinders 40a, 40b, 40c is divided by the stroke number of the modification cylinder 40d is 1 or more.SELECTED DRAWING: Figure 1

Description

The present invention provides at least one reforming cylinder that partially oxidizes at least a part of the air-fuel mixture containing fuel and combustion air to reform it into a reforming gas containing a combustion-promoting gas having a faster combustion rate than the fuel. In addition to the reformed cylinder, a normal cylinder is provided, and a first fuel supply unit for supplying fuel guided to the reformed cylinder is provided, and at least the reformed gas reformed by the reformed cylinder is provided. An engine system configured to lead to the normal cylinder,
Also equipped with at least one reforming cylinder that partially oxidizes at least a part of the air-fuel mixture containing fuel and combustion air to reform the mixture into a reforming gas containing a combustion-promoting gas having a faster combustion rate than the fuel. In addition to having a reforming engine, an external output engine having a normal cylinder in addition to the reforming cylinder is provided, and a first fuel supply unit for supplying fuel guided to the reforming cylinder is provided. It relates to an engine system configured to guide the reformed reformed gas to at least the normal cylinder.

Conventionally, as an engine system, at least one normal cylinder having a combustion chamber for burning an air-fuel mixture containing fuel and combustion air is provided, and at least a part of the air-fuel mixture is partially oxidized in the combustion chamber to be compared with the fuel. It is also known that a reforming cylinder that reforms into a reforming gas containing a combustion-promoting gas having a high combustion speed is provided, and the reforming gas reformed by the reforming cylinder is guided to at least a normal cylinder. (See Patent Document 1).
In the reforming cylinder, for example, a reformed gas containing a combustion-promoting gas having a high combustion rate such as hydrogen can be generated by partially oxidizing a rich mixture containing a fuel containing methane as a main component. .. Then, by guiding the reformed gas to the normal cylinder, for example, the spark propagation velocity in the combustion chamber of the normal cylinder can be increased, misfire or combustion fluctuation can be reduced, and combustion stability can be improved.
The technique disclosed in Patent Document 1 discloses that the rotation speed of the reforming cylinder is changed according to the output of the normal cylinder.

Japanese Patent No. 6323911

In the engine system described so far, when the fuel supply state to the normal cylinder and the reforming cylinder and the stroke volume of each cylinder satisfy specific conditions, the fuel is based on the stroke volume of the normal cylinder or the reforming cylinder. There may be restrictions on the supply amount and the supply amount of combustion air, but the technology disclosed in Patent Document 1 above has not been examined in this regard, and the engine system (normal cylinder) has been changed. There was room for improvement in improving efficiency and expanding the output upper limit (increasing the torque upper limit).

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a fuel supply amount based on the stroke volume of the normal cylinder or the reformed cylinder in a configuration in which the reformed gas from the reformed cylinder is guided to the normal cylinder. It is possible to provide an engine system capable of further improving efficiency and expanding the upper limit of torque (increasing the upper limit of output) while satisfying the restrictions on the supply amount of combustion air.

The engine system to achieve the above purpose is
It is provided with at least one reforming cylinder that partially oxidizes at least a part of the air-fuel mixture containing fuel and combustion air to reform it into a reforming gas containing a combustion-promoting gas having a faster combustion rate than the fuel. Equipped with a normal cylinder in addition to the reformed cylinder
A first fuel supply unit for supplying fuel guided to the reforming cylinder is provided.
An engine system configured to guide the reformed gas reformed in the reformed cylinder to at least the normal cylinder, and the characteristic configuration thereof is.
The total stroke volume, which is the sum of the stroke volumes of all the normal cylinders to which the reformed gas is guided, is larger than the total stroke volume, which is the sum of the stroke volumes of all the reformed cylinders.
The number of strokes of the normal cylinder is the number of strokes of the reforming cylinder based on the stroke volume ratio obtained by dividing the total stroke volume of all the normal cylinders to which the reforming gas is guided by the total stroke volume of the reforming cylinder. The point is that a control device capable of performing stroke number ratio control that fluctuates and controls the stroke number ratio, which is a value divided by, is provided.

A modification equipped with at least one reforming cylinder that partially oxidizes at least a part of the air-fuel mixture containing fuel and combustion air to reform it into a reformed gas containing a combustion-promoting gas whose combustion speed is faster than that of fuel. It has a quality engine and an external output engine equipped with a normal cylinder in addition to the reformed cylinder.
A first fuel supply unit for supplying fuel guided to the reforming cylinder is provided.
An engine system configured to guide the reformed gas reformed in the reformed cylinder to at least the normal cylinder, and its characteristic configuration is:
The total stroke volume, which is the sum of the stroke volumes of all the normal cylinders to which the reformed gas is guided, is larger than the total stroke volume, which is the sum of the stroke volumes of all the reformed cylinders.
The number of strokes of the normal cylinder is the number of strokes of the reforming cylinder based on the stroke volume ratio obtained by dividing the total stroke volume of all the normal cylinders to which the reforming gas is guided by the total stroke volume of the reforming cylinder. The point is that a control device capable of performing stroke number ratio control that fluctuates and controls the stroke number ratio, which is a value divided by, is provided.

The inventors of the present invention control the fuel ratio to be zero by lowering the fuel ratio, which is the ratio of the total fuel supply amount to the normal cylinder to the total fuel supply amount to the reformed cylinder, or the reformed cylinder. It has been found that it is possible to improve the efficiency and reduce the NOx of the engine by supplying only the reformed gas as fuel to the normal cylinder by controlling the supply only to the normal cylinder.
However, as described above, when only the reformed gas is supplied to the normal cylinder as fuel, the fuel supply amount and the combustion air supply amount due to the stroke volume of the normal cylinder or the reformed cylinder are restricted depending on the configuration. It may come.
For example, when the fuel is city gas 13A mainly composed of methane, the excess air ratio of the reforming cylinder is controlled to 0.6, and the excess air ratio of the normal cylinder is controlled to 1.0. When performing control to reduce the fuel ratio, which is the ratio of the total fuel supply to the normal cylinder to the total fuel supply, to make the fuel ratio zero, the gas volume (NL) of the reforming cylinder and the normal cylinder Consider the volume ratio of the gas to the amount of air supply (NL). Here, as the volume, it is assumed that a normal liter converted in an academic standard state where the temperature is 0 ° C., the pressure is atmospheric pressure, and the relative humidity is 0% is used.

As shown in [Table 1], when the excess air ratio of the reforming cylinder is 0.6 and the fuel supply amount to the reforming cylinder is 1.0NL, the supply amount of combustion air to the reforming cylinder is set to 1.0NL. Is 6.48 NL, and the total is 7.48 NL. Since it is known from experiments that about 1.12 times the 7.48 NL is the reformed gas guided to the normal cylinder, the volume is 8.38 NL. .. The air ratio obtained by dividing the amount of air supplied to all cylinders by the amount of air required to completely burn the fuel supplied to all cylinders (hereinafter referred to as "normal cylinder excess air ratio" or "total air excess ratio". The same applies to the one showing the excess air ratio of the normal cylinder that burns the reformed gas in the table), and the amount of combustion air supplied to the normal cylinder is 4.32 NL. The volume ratio of the air supply amount of the quality cylinder to the air supply amount of the normal cylinder is approximately 1.0: 1.7.
Therefore, assuming that the reformed cylinder is one cylinder and the normal cylinder is two cylinders, the ratio of the air supply amount of one reformed cylinder to the air supply amount of one normal cylinder is 1.0: 0.85. The volume is almost balanced, and the throttle can be opened when the combustion air is normally supplied to the cylinder, and the pump loss can be suppressed.
On the other hand, in a 4-cylinder internal combustion engine with the same stroke volume (equal displacement), 1 cylinder is a reforming cylinder, 3 cylinders are normal cylinders, and the total amount of fuel supplied to the reforming cylinders is the total to the normal cylinders. If the control to reduce the fuel ratio, which is the ratio of the fuel supply amount, to zero is executed, the volume balance will be greatly deviated, and the throttle that normally supplies combustion air to the cylinder will be controlled to the closed side. The need arises and the pump loss in the normal cylinder increases.

On the other hand, there are cases where the upper limit of torque is lowered (the upper limit of output is lowered).
First, in a 4-cylinder internal combustion engine having the same stroke volume, when the 4-cylinder is a normal cylinder, the stroke volume of one cylinder is 60 NL, and all cylinders are operated with an excess air ratio of 1.5, as shown in [Table 2]. In addition, in each of all cylinders, the fuel supply amount is 3.49 NL, the combustion air supply amount is 56.51 NL, and the gas filling rate to each cylinder is 100%.

On the other hand, in a 4-cylinder internal combustion engine having the same stroke volume, 3 cylinders are normal cylinders, 1 cylinder is a reforming cylinder, the excess air ratio of the normal cylinder is 1.0, and the excess air ratio of the reforming cylinder is 0. As 6.6, when the control to reduce the fuel ratio, which is the ratio of the total fuel supply amount to the normal cylinder to the total fuel supply amount to the reforming cylinder, to make the fuel ratio zero is executed, it can be input to the reforming cylinder. The upper limit of the amount of fuel depends on the lower limit of the excess air rate of the reforming cylinder. When the lower limit of the excess air ratio of the reformed cylinder is, for example, 0.6, 60 NL, which is the volume of the total supply amount of fuel and combustion air to the reformed cylinder, is set as shown in [Table 3]. The reformed gas multiplied by 1.12 can be guided to the normal cylinder, which is divided into three equal parts and guided to each of the normal cylinders. In the normal cylinder, 11.55 NL of combustion air is supplied to each normal cylinder in order to make the excess air ratio of the normal cylinder 1.0, and the total amount of fuel and combustion air supplied to each normal cylinder is. It becomes 33.95 NL, the gas filling rate to the normal cylinder is 56.6%, the average gas filling rate of the four cylinders is 67.4%, and the above-mentioned four cylinders are used as the normal cylinder and the excess air rate is 1.5. It is lower than the gas filling rate of 100% when operating, and if the net thermal efficiencies of both are the same, the amount of fuel that can be filled is 57.5% (= 8.02 / 13.96 x 100). Therefore, the upper limit of torque is also lowered.

Therefore, in the present invention, the upper limit of the torque is expanded while maintaining the volumetric balance of the gas between the normal cylinder and the reforming cylinder (the gas filling rate to the reforming cylinder and the gas filling rate to the normal cylinder). In order to increase the upper limit of the output), the total stroke volume, which is the sum of the stroke volumes of all the normal cylinders to which the reforming gas is guided, is larger than the total stroke volume, which is the sum of the stroke volumes of all the reforming cylinders. , The control device divides the total stroke volume of all normal cylinders to which the reforming gas is guided by the total stroke volume of the reforming cylinder, and divides the stroke number of the normal cylinder by the stroke number of the reforming cylinder. The stroke number ratio control that fluctuates and controls the stroke number ratio, which is the divided value, by 1 or more is executed.
According to the above characteristic configuration, for example, in a 4-cylinder internal combustion engine having the same stroke volume, 3 cylinders are normal cylinders, 1 cylinder is a reformed cylinder, a normal cylinder excess air ratio is 1.0, and air in the reformed cylinders. When performing control to reduce the fuel ratio, which is the ratio of the total fuel supply amount to the normal cylinder to the total fuel supply amount to the reforming cylinder, to make the fuel ratio zero, with the excess rate set to 0.6, the control device. However, the stroke number ratio control can be executed based on the stroke volume ratio, and for example, the reforming cylinder can be burned in a 2-stroke cycle, and the normal cylinder can be burned in a 4-stroke cycle. As a result, as shown in [Table 4], the stroke volume of the cylinder in the reformed cylinder for 4 strokes (1 cycle of the normal cylinder) becomes twice that of 60NL, so that the stroke volume is 4 strokes (1 of the normal cylinder). The amount of fuel that can be charged into the reformed cylinder can be increased to 14.18 NL in the cycle), the amount of reformed gas that can be supplied to the normal cylinder increases, the filling efficiency of the normal cylinder can be increased to about 100%, and the amount of fuel that can be filled It becomes 101.6% (= 14.18 / 13.96 × 100), and the upper limit of torque can be improved.

As a result, the volume balance between the reforming cylinder and the normal cylinder (gas filling rate to the reforming cylinder and gas filling rate to the normal cylinder) can be maintained, pump loss can be reduced, and efficiency can be improved. On the other hand, the filling efficiency of the normal cylinder can be made equal to the filling efficiency when the above-mentioned four cylinders are used as normal cylinders and the excess air ratio is 1.5, and the torque upper limit can be expanded (the output upper limit can be expanded). Can provide an engine system.

It should be noted that the total stroke volume of all the normal cylinders to which the reforming gas is guided is calculated by the total stroke volume of the reforming cylinder without providing a control device for executing the stroke number ratio control as described above. A configuration may be adopted in which the stroke number ratio, which is the value obtained by dividing the stroke number of the normal cylinder by the stroke number of the reforming cylinder, is 1 or more based on the divided stroke volume ratio.

Further features of the engine system
In the control device, the larger the stroke volume ratio obtained by dividing the total stroke volume of all the normal cylinders to which the reforming gas is guided by the total stroke volume of the reforming cylinder, the more the stroke number in the stroke number ratio control. The point is to control the ratio greatly.

According to the above characteristic configuration, in the control device, the larger the stroke volume ratio obtained by dividing the total stroke volume of all the normal cylinders to which the reforming gas is guided by the total stroke volume of the reforming cylinder, the more strokes in the stroke number ratio control. Since the ratio is largely controlled, for example, when operating by changing the number of normal cylinders and the number of reforming cylinders, the stroke ratio is changed to the optimum stroke ratio according to the stroke volume ratio to improve efficiency. The upper limit of torque can be expanded.

Further features of the engine system
At least a second fuel supply unit that supplies fuel guided to the normal cylinder and a first fuel supply unit that supplies fuel guided to the reforming cylinder are separately provided.
The control device executes air excess rate fluctuation control that adjusts the fuel supply amount by the first fuel supply unit and fluctuates the air excess rate in the reforming cylinder within a predetermined range for generating reformed gas. In the state of
Fuel ratio reduction that reduces the fuel ratio, which is the ratio of the total fuel supply amount to all the normal cylinders by the second fuel supply unit to the total fuel supply amount to all the reforming cylinders by the first fuel supply unit. The point is to execute control.

Further, it is preferable that the control device controls the fuel ratio by the fuel ratio reduction control to 0.0 or more and 0.50 or less while the air excess rate fluctuation control is being executed.

As described above, the thermal efficiency can be improved and the NOx can be reduced by controlling the fuel ratio reduction to bring the fuel ratio closer to zero as in the above-mentioned characteristic configuration.
However, as described above, when the fuel ratio reduction control is executed, the balance of the volume ratio between the normal cylinder and the modified cylinder may be greatly disturbed and the pump loss may increase, and the torque upper limit of the normal cylinder may be significantly increased. There may be restrictions.
Therefore, by executing the fuel ratio reduction control together with the stroke number ratio control in the present invention, it is expected that the pump loss can be reduced and the thermal efficiency can be further improved while enjoying the merits of the fuel ratio reduction control and the torque upper limit. An engine system that can be expanded well is achieved.

Further features of the engine system
The control device adjusts the amount of fuel supplied by the first fuel supply unit, the amount of air supplied to the reformed cylinder, or both to generate a reformed gas at an excess air ratio in the reformed cylinder. The point is to execute a reformed gas operation that guides only the reformed gas as the fuel to the normal cylinder while executing the air excess rate fluctuation control that fluctuates and controls the fluctuation within a predetermined range.

As described above, the characteristic configuration is also improved in thermal efficiency and reduced in NOx by operating the reformed gas that guides only the reformed gas as fuel to the normal cylinder and bringing the fuel ratio close to zero. Can be planned.
However, as described above, when the reformed gas operation is executed, the balance of the volume ratio between the normal cylinder and the reformed cylinder may be greatly disturbed and the pump loss may increase, and the torque upper limit of the normal cylinder may be significantly increased. There may be restrictions.
Therefore, by executing the reformed gas operation together with the stroke number ratio control in the present invention, it is expected that the pump loss is reduced and the thermal efficiency is further improved while enjoying the merits of the reformed gas operation, and the torque upper limit is increased. An engine system that can be expanded well is achieved.

Further features of the engine system
At startup, the control device executes a reformed cylinder high output operation in which the output in the reformed cylinder is temporarily increased prior to the reformed gas operation.

In the configuration where fuel is not directly supplied to the cylinder as in the above characteristic configuration, a configuration in which assist operation is performed by a starter motor at startup can be considered. For example, the flow rate of fresh air guided to the reforming cylinder is increased. By doing so, the stability of the engine system at the time of starting can be further improved by temporarily increasing the output of the reforming cylinder.

Schematic block diagram of the engine system according to the first embodiment of the present invention Conceptual diagram for explaining two-stroke cycle operation of modified cylinder and normal cylinder Conceptual diagram for explaining 4-stroke cycle operation of modified cylinder and normal cylinder Conceptual diagram for explaining 6-stroke cycle operation of modified cylinder and normal cylinder Conceptual diagram for explaining 8-stroke cycle operation of modified cylinder and normal cylinder Schematic block diagram of the engine system according to the second embodiment of the present invention Schematic block diagram of the engine system according to the third embodiment of the present invention Schematic block diagram of the engine system according to the fourth embodiment of the present invention

The engine system 100 according to the embodiment of the present invention has a configuration in which the reformed gas from the reformed cylinder is guided to the normal cylinder, and the fuel supply amount and the combustion air supply amount based on the stroke volume of the normal cylinder or the reformed cylinder. The present invention relates to a system capable of further improving efficiency and expanding the upper limit of torque (increasing the upper limit of output) while satisfying the restrictions.
Hereinafter, the configuration of the engine system 100 will be described with reference to the drawings.

[First Embodiment]
As shown in FIG. 1, the engine system 100 according to the first embodiment usually burns an air-fuel mixture M containing fuel F such as city gas 13A (an example of fuel) and combustion air A in the engine body 40. The cylinders 40a, 40b, and 40c are provided with a reforming cylinder 40d that partially oxidizes at least a part of the air-fuel mixture M and reforms it into a reforming gas K containing a combustion-promoting gas having a combustion speed faster than that of the fuel F. A second fuel supply unit that supplies fuel guided to the normal cylinders 40a, 40b, and 40c and a first fuel supply unit that supplies fuel guided to the reforming cylinder 40d are separately provided, and the reforming cylinder 40d is provided. The reformed reformed gas K is guided to at least the normal cylinders 40a, 40b, 40c (in the first embodiment, it is guided only to the normal cylinders 40a, 40b, 40c).

The engine system 100 of the first embodiment is configured as a turbocharged engine, and has at least one (three in the first embodiment) normal cylinders 40a, 40b, 40c and at least one or more. It is provided with a modified cylinder 40d (one in the first embodiment). Furthermore, an engine control unit consisting of a hardware group and a software group that control the operation of a turbocharged engine based on the input signal of measurement results of a sensor or the like that detects the operating state of the engine. (Hereinafter referred to as a control device 50).

Although detailed illustration is omitted, this type of engine system 100 supplies air from the air supply main 20 to the combustion chambers (not shown) of the normal cylinders 40a, 40b, 40c via an air supply valve (not shown). By igniting sparks with an ignition plug (not shown) in a state where the fresh air is compressed by the rise of the piston and burning and expanding it, the piston is pushed down and rotational power is output from the rotating shaft (not shown). At the same time, the exhaust gas E generated by combustion is pushed out from the combustion chambers of the normal cylinders 40a, 40b, and 40c to the exhaust passage 27 via an exhaust valve (not shown) and discharged to the outside.
Although the details will be described later, the combustion air A supplied from the air supply main pipe 20 is also supplied to the reforming cylinder 40d through the reforming cylinder air supply branch pipe 20d, and the piston is pushed down even in the reforming cylinder 40d. Outputs rotational power from the rotating shaft. However, all of the reformed gas K generated as exhaust gas in the reformed cylinder 40d is returned to the air supply main 20 via the reformed gas passage 28 without being discharged to the outside. It will be guided to the normal cylinders 40a, 40b, 40c.

The air supply main 20 includes an air cleaner 21 that purifies the combustion air A, a Venturi type mixer 14 that mixes the fuel F with the combustion air A at an appropriate ratio (air-fuel ratio), and a normal cylinder 40a by adjusting the opening degree. Throttle valves 23 for normal cylinders capable of adjusting the amount of air supplied to the air-fuel mixture M to 40b and 40c are provided in the order described from the upstream side thereof.
That is, in the air supply main 20, the air-fuel mixture M generated by mixing the fuel F and the combustion air A with the mixer 14 is adjusted to a predetermined flow rate via the throttle valve 23 for the normal cylinder, and is usually It is introduced into the combustion chambers of the cylinders 40a, 40b and 40c.

The air supply branch pipe 20d for the reforming cylinder, which branches from the air supply main 20 to the upstream side of the mixer 14, has a compressor 31 as a supercharger 30 for compressing the combustion air A, and the temperature is raised by boosting the pressure of the compressor 31. An intercooler 22 that cools the combustion air A, a throttle valve 25 for the reforming cylinder that can adjust the amount of air supply of the air-fuel mixture M to the reforming cylinder 40d by adjusting the opening degree, and an appropriate fuel F for the combustion air A. Ventury type mixers 16 that mix at a ratio (air-fuel ratio) are provided in the order described from the upstream side thereof.

In the second fuel supply path 11 that guides the fuel F to the mixer 14, the pressure difference between the pressure of the combustion air A in the air supply main 20 on the upstream side of the mixer 14 and the fuel F in the second fuel supply path 11 is made constant. A second fuel flow control valve 13 for adjusting the supply amount of fuel F supplied to the combustion chambers of the normal cylinders 40a, 40b, and 40c via the differential pressure regulator 12 and the mixer 14 to be maintained is provided. That is, the second fuel supply path 11, the differential pressure regulator 12, the mixer 14, and the second fuel flow rate control valve 13 function as the second fuel supply unit.

The supercharger 30 supplies the exhaust gas E discharged from the normal cylinders 40a, 40b, 40c to the turbine 32 provided in the exhaust passage 27 connected to the normal cylinders 40a, 40b, 40c, and is connected to the turbine 32. It is configured as a turbocharger 30 that compresses the air-fuel mixture M supplied to the combustion chamber of the reforming cylinder 40d by a compressor 31 provided in the reforming cylinder air supply branch pipe 20d in this state. That is, the supercharger 30 rotates the turbine 32 by the kinetic energy of the exhaust gas E passing through the exhaust passage 27, and the combustion air passing through the air supply branch pipe 20d for the reforming cylinder by the rotational force of the turbine 32. So-called supercharging is performed in which A is compressed and supplied to the combustion chamber of the reforming cylinder 40d.
That is, in the first embodiment, the supercharger 30 supercharges only the combustion air A guided to the reforming cylinder 40d.

The air supply main 20 is connected to a plurality of normal cylinder air supply branch pipes 20a, 20b, 20c that guide combustion air A2 to each of the normal cylinders 40a, 40b, 40c on the downstream side of the air cleaner 21. It is branched into a pipe 20 and an air supply branch pipe 20d for a reforming cylinder that guides combustion air A to the reforming cylinder 40d.
The reformed cylinder 40d partially oxidizes a part of the fresh air in its own combustion chamber, and the reformed gas K containing a combustion-promoting gas such as hydrogen, which has a faster combustion rate than the fuel F (for example, methane). Is configured to generate. Here, it is known that when hydrogen is burned by mixing methane and air, the amount of hydrogen generated has a peak in the fuel enrichment region where the excess air ratio is less than 1.
Therefore, in the first embodiment, the air supply branch pipe 20d for the reforming cylinder that supplies fresh air to the reforming cylinder 40d in order to burn the air-fuel mixture in the fuel chamber of the reforming cylinder 40d in a fuel-rich state. A first fuel supply path 29 for supplying the fuel F is connected to the first fuel supply path 29 via a venturi-type mixer 16, and a first fuel flow rate control for controlling the flow rate of the fuel F is connected to the first fuel supply path 29. A valve 15 is provided. On the upstream side of the first fuel flow rate control valve 15 of the first fuel supply path 29, a compressor (not shown) is used to increase the supply pressure of the fuel F to the supercharging pressure at the outlet of the compressor 31 of the air supply main 20. ) Etc. are provided.
Further, the reformed gas passage 28 through which the reformed gas K reformed by the reformed cylinder 40d flows is connected to the reformed cylinder 40d, and is downstream of the reformed gas passage 28. The end is connected to the downstream side of the normal cylinder throttle valve 23 of the air supply main 20. That is, in the first embodiment, all of the reformed gas K is configured to be guided to the normal cylinders 40a, 40b, 40c.
The control device 50 controls the opening degree of the first fuel flow rate control valve 15 so that the excess air ratio of fresh air to the reforming cylinder 40d is smaller than 1. That is, the first fuel supply path 29, the mixer 16, and the first fuel flow rate control valve 15 function as the first fuel supply unit.

The rotation shaft (not shown) of the engine body 40 is provided with a rotation speed sensor for measuring the rotation speed of the rotation shaft (not shown) as an operating state detection unit 41.
Further, the rotation shaft (not shown) of the engine body 40 is provided with a torque measurement sensor for measuring the torque of the rotation shaft as an operating state detection unit 41, and the control device 50 is, for example, a rotation speed sensor. The second fuel flow control valve 13 and the first fuel flow control valve so that the engine output calculated based on the engine speed measured by the torque measurement sensor and the torque measured by the torque measurement sensor becomes the target output. 15. Controls the opening degree of the throttle valve 23 for a normal cylinder and the throttle valve 25 for a reforming cylinder.
All the normal cylinders 40a, 40b, 40c, and the reformed cylinder 40d are provided with an in-cylinder pressure sensor (not shown) for detecting the in-cylinder pressure as an operating state detection unit 41, and the control device 50 , Various controls described later are executed based on the measurement result of the in-cylinder pressure sensor. Further, the control device 50 is configured to be able to acquire the measurement result of the supply air temperature sensor (not shown) that measures the supply air temperature, and various controls to be described later based on the measurement result of the supply air temperature sensor. To execute.

By the way, the engine system 100 according to the embodiment executes the following control in order to improve the thermal efficiency and the exhaust gas properties in the engine system including the normal cylinders 40a, 40b, 40c and the reformed cylinder 40d. ..
The control device 50 adjusts the fuel supply amount by the first fuel flow rate control valve 15 as the first fuel supply unit to control the excess air ratio in the reforming cylinder 40d within a predetermined range for generating the reforming gas K. Total fuel supply to all reforming cylinders 40d (1 cylinder in the first embodiment) by the first fuel flow control valve 15 as the first fuel supply unit while executing the air excess rate fluctuation control. Decrease the fuel ratio, which is the ratio of the total fuel supply amount to all the normal cylinders 40a, 40b, 40c (three cylinders in the first embodiment) by the second fuel flow control valve 13 as the second fuel flow control valve 13 to the amount. Perform fuel ratio reduction control.

In the air excess rate fluctuation control, when a hydrocarbon gas containing methane as a main component is used as the fuel, the total air excess rate of the normal cylinders 40a, 40b, 40c and the reformed cylinder 40d is 1.0 or more and 1.5. The excess air rate in the reformed cylinder 40d is adjusted as follows, and the fuel supply amount by the first fuel flow control valve 15 as the first fuel supply unit and / or the opening degree of the reforming cylinder throttle valve 25 are adjusted. It is preferable to control the fluctuation in the range of 0.5 or more and 0.9 or less (more preferably 0.55 or more and 0.8 or less).
The fuel ratio controlled by the fuel ratio reduction control is preferably controlled to 0.0 or more and 0.50 or less.
As a result, the NOx concentration of the exhaust gas E discharged from the normal cylinders 40a, 40b, 40c can be maintained below the target value (for example, 150 ppm at the target value set as a voluntary standard), and the efficiency of the entire system can be improved. ..

Further, in the engine system 100 according to the first embodiment, the control device 50 reduces the total stroke volume (total displacement) of all the normal cylinders 40a, 40b, 40c to which the reforming gas K is guided. A stroke that fluctuates and controls the stroke number ratio, which is the value obtained by dividing the stroke numbers of the normal cylinders 40a, 40b, and 40c by the stroke number of the modified cylinder 40d, based on the stroke volume ratio divided by the total stroke volume of 40d. It is configured to enable number ratio control.

To add a description, in the first embodiment, the intake valve (not shown) and the exhaust valve (not shown) provided in each of the normal cylinders 40a, 40b, 40c and the modified cylinder 40d are particularly provided. ) Is provided with a valve operating mechanism capable of changing the gear ratio between the camshaft (not shown) of the cam for setting the opening / closing timing and the rotating shaft (not shown) of the engine body 40.
That is, the control device 50 controls the valve operating mechanism, and as shown in FIG. 2, sets the intake stroke, the compression stroke, the expansion stroke, and the exhaust stroke as top dead center (TDC) and bottom dead center (BDC), respectively. A 4-stroke cycle that executes 1 stroke between the two strokes, a 2-stroke cycle that executes expansion, exhaust, intake, and compression in 2 strokes as shown in FIG. 3, and 4 strokes as shown in FIGS. A pair that closes both the intake valve and the exhaust valve without burning between the intake stroke and the compression stroke for the cycle, and reciprocates the pistons of the reforming cylinders 40d, 40b, 40c and the reforming cylinder 40d. The stroke number ratio control can be executed in a form in which at least one or more stroke cycles (6 stroke cycles in FIG. 4 and 8-stroke cycles in FIG. 5 are exemplified) are executed separately. It is configured.
However, it is assumed that the two-stroke cycle is not executed in the normal cylinders normal cylinders 40a, 40b and 40c.
An example of the open / closed state of the intake valve and the exhaust valve by the valve operating mechanism for each of the above-mentioned 4-stroke cycle, 2-stroke cycle, and 6- and 8-stroke cycle will be described. In the 4-stroke cycle, the valve operating mechanism is shown in FIG. As shown in 2, the intake valve is opened and the compression stroke, the expansion stroke and the exhaust stroke are closed, and the exhaust valve is opened to the exhaust stroke and the intake stroke, the compression stroke and the expansion stroke. Closed.
In the 6-stroke cycle, as shown in FIG. 4, the valve operating mechanism opens the intake valve to the intake stroke, and also has a pair of rest strokes (sealed ascending stroke and sealed descending stroke), compression stroke, expansion stroke, and exhaust stroke. The exhaust valve is closed in the exhaust stroke, and the intake stroke, a pair of pause strokes (sealed ascending stroke and sealed descending stroke), compression stroke, and expansion stroke are closed.
In the 8-stroke cycle, as shown in FIG. 5, the valve operating mechanism opens the intake valve to the intake stroke and two pairs of rest strokes (sealed ascending stroke, sealed descending stroke, sealed ascending stroke, and sealed descending stroke). The compression stroke, expansion stroke, and exhaust stroke are closed, the exhaust valve is opened to the exhaust stroke, and the intake stroke and two pairs of pause strokes (sealed ascending stroke, sealed descending stroke, sealed ascending stroke, and sealed descending stroke). ), The compression stroke and the expansion stroke are closed.
In the two-stroke cycle, as shown in FIG. 3, the valve operating mechanism opens the intake valve at 135 ° ATDC to 270 ° ATDC with reference to the top dead center, and 0 ° ATDC to 135 ° ATDC and 270 ° ATDC. The closed state is set at ~ 360 ° ATDC, the exhaust valve is opened at 90 ° ATDC to 270 ° ATDC, and the closed state is set at 0 ° ATDC to 90 ° ATDC and 270 ° ATDC to 360 ° ATDC.

In the first embodiment, the control device 50 has a compression stroke of 60 ° BTDC to 10 ° ATDC in any of the 2-stroke cycle, 4-stroke cycle, 6-stroke cycle, and 8-stroke cycle. It is configured to set the ignition timing of the reforming cylinder 40d between.

By executing the stroke number ratio control as described above, as described in [Means for Solving the Problem], the gas filling rate of the reforming cylinder 40d and the gas filling of the normal cylinders 40a, 40b, 40c It is possible to maintain a balance with the rate, reduce pump loss and improve efficiency, while expanding the upper limit of torque (increasing the upper limit of output) in the normal cylinders 40a, 40b, 40c. it can.

Incidentally, as in the first embodiment, in a configuration in which the normal cylinders 40a, 40b, 40c are provided with three cylinders and the reforming cylinder 40d is provided with one cylinder, the excess air ratio of the reforming cylinder 40d is set to 0.6, and the normal cylinders 40a, 40b , When the total excess air ratio of 40c is controlled to 1.0 and the fuel ratio is controlled to 0.0 by the above-mentioned fuel ratio reduction control, the reformed cylinder 40d is burned in a 2-stroke cycle and the normal cylinder. By burning 40a, 40b, and 40c in a 4-stroke cycle, as shown in [Table 4] above, the gas filling rate of the reforming cylinder 40d and the gas filling rate of the normal cylinders 40a, 40b, 40c are almost balanced. Can be kept. At this time, if the reformed cylinder 40d is burned in a two-stroke cycle, a part of the fuel F is not burned in the reformed cylinder 40d, but the unburned fuel is the normal cylinders 40a and 40b together with the reformed gas K. It is properly burned at 40c.

[Second Embodiment]
In the engine system 100 according to the first embodiment, there is a configuration example in which the reformed gas K reformed by the reformed cylinder 40d is guided to the normal cylinders 40a, 40b, 40c in a single multi-cylinder engine. Indicated.
As shown in FIG. 6, the engine system 200 according to the second embodiment is in addition to the reforming engine 200a having a reforming cylinder 40d for reforming the air-fuel mixture M to generate the reforming gas K. It is configured to include an external output engine 200b having normal cylinders 80a, 80b, 80c, 80d to which the reformed gas K generated by the reforming engine 200a is guided.

In the engine system 200, measurement results of a sensor or the like for detecting the operating state of the external output engine 200b are input, and the hardware group and the software group that control the operation of the external output engine 200b based on the input signal are used. It includes an engine control unit (hereinafter, referred to as a control device 50) that is configured. That is, the engine system 200 according to the second embodiment is configured to positively detect the operating state of the external output engine 200b instead of the reforming engine 200a.
In the modified engine 200a in the engine system 200 according to the second embodiment, the normal cylinders 40a, 40b, 40c in the engine system 100 according to the first embodiment are set to non-modified cylinders 40d, 40b, 40c, and the supply for the normal cylinder is provided. The bronchial tubes 20a, 20b, 20c are designated as non-reforming cylinder supply bronze tubes 20a, 20b, 20c.
Further, in the engine system 200 according to the second embodiment, the reformed gas K generated in the reformed cylinder 40d is not returned to the air supply main 20 of the reformed engine 200a, that is, the non-reformed cylinder. The reformed gas K is not guided to the air supply branch pipes 20a, 20b, 20c, and the non-reformed cylinders 40d, 40b, 40c to which they are connected.
Further, in the engine system 200 according to the second embodiment, the fuel F supplied via the second fuel supply path 11, the differential pressure regulator 12, the mixer 14, and the second fuel flow rate control valve 13 is unmodified. In addition to the cylinders 40d, 40b, and 40c, it is configured to lead to the reforming cylinder 40d. In the first embodiment, the second fuel supply path 11, the differential pressure regulator 12, the mixer 14, and the second fuel flow rate control valve 13 act as the second fuel supply unit, but the second embodiment. In the embodiment, the second fuel supply unit is realized by another configuration described later.

Except for the above points, the modified engine 200a in the engine system 200 according to the second embodiment has substantially the same configuration as the engine system 100 according to the first embodiment described above, and has the same control. Execute.
Hereinafter, the configuration and control different from those of the engine system 200 according to the first embodiment will be described with emphasis, and the detailed description of the same configuration and control may be omitted.

As shown in FIG. 6, the external output engine 200b supplies air from the air supply main 70 to the combustion chambers (not shown) of the normal cylinders 80a, 80b, 80c, 80d via an air supply valve (not shown). By igniting sparks with an ignition plug in a state where the fresh air is compressed by the rise of the piston and burning and expanding it, the piston is pushed down and rotational power is output from the rotating shaft (not shown), and it is generated by combustion. The exhaust gas E is normally pushed out from the combustion chambers of the cylinders 80a, 80b, 80c, and 80d to the exhaust passage through an exhaust valve (not shown) and discharged to the outside.

The air supply main 70 includes an air cleaner 71 that purifies the combustion air A, a Venturi type mixer 64 that mixes the fuel F with the combustion air A at an appropriate ratio (air-fuel ratio), and a normal cylinder 80a by adjusting the opening degree. Throttle valves 73 capable of adjusting the amount of air supplied to the air-fuel mixture M to 80b, 80c, and 80d are provided in the order described from the upstream side thereof.
That is, in the air supply main 70, the air-fuel mixture M generated by mixing the fuel F and the combustion air A with the mixer 64 is adjusted to a predetermined flow rate via the throttle valve 73, and the normal cylinders 80a and 80b are used. , 80c, 80d introduced into the combustion chamber.

In the third fuel supply path 61 that guides the fuel F to the mixer 64, the pressure difference between the pressure of the combustion air A in the air supply main 70 on the upstream side of the mixer 64 and the fuel F in the third fuel supply path 61 is made constant. A third fuel flow control valve 63 for adjusting the supply amount of the fuel F supplied to the combustion chambers of the normal cylinders 80a, 80b, 80c, and 80d via the differential pressure regulator 62 and the mixer 64 is provided.
That is, the third fuel supply path 61, the mixer 64, and the third fuel flow rate control valve 63 function as the second fuel supply unit.

The rotation shaft (not shown) of the engine body 80 of the external output engine 200b is provided with a rotation speed sensor for measuring the rotation speed of the rotation shaft (not shown) as an operating state detection unit 81, and is a control device. 50 controls the opening degree of the throttle valve 73 based on the measurement result of the rotation speed sensor in order to maintain the engine rotation speed measured by the rotation speed sensor at the target rotation speed.
Further, the rotation shaft (not shown) of the engine body 80 of the external output engine 200b is provided with a torque measurement sensor for measuring the torque of the rotation shaft as an operating state detection unit 81, and the control device 50 is provided with a torque measurement sensor. For example, the first fuel flow control valve 15, the first, so that the engine rotation speed measured by the rotation speed sensor and the engine output calculated based on the torque measured by the torque measurement sensor become the target output. 3 The opening degree of the fuel flow control valve 63, the throttle valve 23 for a normal cylinder, and the throttle valve 73 is controlled.
All the normal cylinders 80a, 80b, 80c, 80d are provided with an in-cylinder pressure sensor for detecting the in-cylinder pressure as an operating state detection unit 81, and the control device 50 is a measurement result of the in-cylinder pressure sensor. Based on the above, various controls described later are executed. Further, the control device 50 is configured to be able to acquire the measurement result of the supply air temperature sensor (not shown) that measures the supply air temperature (the supply air temperature of the external output engine 200b or the supply air temperature of the reforming engine 200a). Based on the measurement result of the supply air temperature sensor, various controls described later are executed.

The air supply main pipe 70 is connected to a plurality of air supply branch pipes 70a, 70b, 70c, 70d that guide the air-fuel mixture M to the normal cylinders 80a, 80b, 80c, 80d on the downstream side of the throttle valve 73.
On the downstream side of the throttle valve 73 in the air supply main 70, and on the upstream side of the plurality of air supply branch pipes 70a, 70b, 70c, 70d, the reformed gas generated by the reforming cylinder 40d of the reforming engine 200a The reformed gas flow path 28 through which K passes is communicated and connected. With this configuration, the reformed gas K flows through all of the above-mentioned air supply branch pipes 70a, 70b, 70c, and 70d at substantially the same flow rate.

In the engine system 200 configured as described above, the following control is executed in order to improve the thermal efficiency and the exhaust gas properties.
The control device 50 adjusts the fuel supply amount by the first fuel flow rate control valve 15 as the first fuel supply unit to control the excess air ratio in the reforming cylinder 40d within a predetermined range for generating the reforming gas K. Total fuel supply to all reforming cylinders 40d (1 cylinder in the second embodiment) by the first fuel flow rate control valve 15 as the first fuel supply unit while executing the air excess rate fluctuation control. The fuel ratio, which is the ratio of the total fuel supply amount to all the normal cylinders 80a, 80b, 80c, 80d (4 cylinders in the second embodiment) by the third fuel flow rate control valve 63 as the second fuel supply unit to the amount. The total stroke volume (total displacement) of all the normal cylinders 80a, 80b, 80c, 80d to which the reforming gas K is guided is divided by the total stroke volume of the reforming cylinder 40d while executing the fuel ratio reduction control to reduce the fuel ratio. Based on the stroke volume ratio, the stroke number ratio control that fluctuates and controls the stroke number ratio, which is the value obtained by dividing the stroke numbers of the normal cylinders 80a, 80b, 80c, and 80d by the stroke number of the modified cylinder 40d, is executed. To do.
The details of the excess air ratio fluctuation control, the fuel ratio reduction control, and the stroke number ratio control are the same as those of the engine system 100 according to the first embodiment, and therefore the detailed description thereof will be omitted here.

[Third Embodiment]
In the engine system 100 according to the third embodiment, as shown in FIG. 7, at least a part of the air-fuel mixture M containing the fuel F such as city gas 13A and the combustion air A is partially oxidized in the engine body 40. It is provided with at least one reforming cylinder 40d for reforming into reforming gas K containing combustion promoting gas having a combustion speed faster than that of fuel F, and is provided with normal cylinders 40a, 40b, 40c in addition to the reforming cylinder 40d. A first fuel supply unit for supplying fuel guided to the reforming cylinder 40d is provided, and the reformed gas K reformed by the reforming cylinder 40d is guided to at least the normal cylinders 40a, 40b, 40c (the third). In the embodiment, it usually leads only to the cylinders 40a, 40b, 40c).

Hereinafter, the engine system 100 according to the third embodiment will be described with reference to FIG. 7.
The engine system 100 of the third embodiment is configured as a turbocharged engine, and has at least one (three in the third embodiment) normal cylinders 40a, 40b, 40c and at least one or more. It is provided with a modified cylinder 40d (one in the third embodiment). Furthermore, an engine control unit consisting of a hardware group and a software group that control the operation of a turbocharged engine based on the input signal of measurement results of a sensor or the like that detects the operating state of the engine. (Hereinafter referred to as a control device 50).

Although detailed illustration is omitted, this type of engine system 100 supplies air from the air supply main 20 to the combustion chambers (not shown) of the normal cylinders 40a, 40b, 40c via an air supply valve (not shown). By igniting sparks with an ignition plug (not shown) in a state where the fresh air is compressed by the rise of the piston and burning and expanding it, the piston is pushed down and rotational power is output from the rotating shaft (not shown). At the same time, the exhaust gas E generated by combustion is pushed out from the combustion chambers of the normal cylinders 40a, 40b, and 40c to the exhaust passage 27 via an exhaust valve (not shown) and discharged to the outside.
Although the details will be described later, the combustion air A supplied from the air supply main pipe 20 is also supplied to the reforming cylinder 40d through the reforming cylinder air supply branch pipe 20d, and the piston is pushed down even in the reforming cylinder 40d. Outputs rotational power from the rotating shaft. However, all of the reformed gas K generated as exhaust gas in the reformed cylinder 40d is returned to the air supply main 20 via the reformed gas passage 28 without being discharged to the outside. It will be guided to the normal cylinders 40a, 40b, 40c.

The air supply main 20 is provided with an air cleaner 21 that purifies the combustion air A.
The air supply main 20 is connected to a plurality of normal cylinder air supply branch pipes 20a, 20b, 20c that guide combustion air A2 to each of the normal cylinders 40a, 40b, 40c on the downstream side of the air cleaner 21. It is branched into a pipe 20 and an air supply branch pipe 20d for a reforming cylinder that guides combustion air A to the reforming cylinder 40d.
The air supply branch pipe 20d for the reforming cylinder, which branches from the air supply main 20 to the downstream side of the air cleaner 21, has a compressor 31 as a supercharger 30 for compressing the combustion air A, and the temperature is raised by boosting the pressure of the compressor 31. An intercooler 22 that cools the combustion air A, a throttle valve 25 for the reforming cylinder that can adjust the amount of air supply of the air-fuel mixture M to the reforming cylinder 40d by adjusting the opening degree, and an appropriate fuel F for the combustion air A. Ventury type mixers 16 that mix at a ratio (air-fuel ratio) are provided in the order described from the upstream side thereof.

The supercharger 30 supplies the exhaust gas E discharged from the normal cylinders 40a, 40b, 40c to the turbine 32 provided in the exhaust passage 27 connected to the normal cylinders 40a, 40b, 40c, and is connected to the turbine 32. It is configured as a turbocharger 30 that compresses the air-fuel mixture M supplied to the combustion chamber of the reforming cylinder 40d by a compressor 31 provided in the reforming cylinder air supply branch pipe 20d in this state. That is, the supercharger 30 rotates the turbine 32 by the kinetic energy of the exhaust gas E passing through the exhaust passage 27, and the combustion air passing through the air supply branch pipe 20d for the reforming cylinder by the rotational force of the turbine 32. So-called supercharging is performed in which A is compressed and supplied to the combustion chamber of the reforming cylinder 40d.
That is, in the third embodiment, the supercharger 30 supercharges only the combustion air A guided to the reforming cylinder 40d.

The reformed cylinder 40d partially oxidizes a part of the fresh air in its own combustion chamber, and the reformed gas K containing a combustion-promoting gas such as hydrogen, which has a faster combustion rate than the fuel F (for example, methane). Is configured to generate. Here, it is known that when hydrogen is burned by mixing methane and air, the amount of hydrogen generated has a peak in the fuel enrichment region where the excess air ratio is less than 1.
Therefore, in the third embodiment, the air supply branch pipe 20d for the reforming cylinder that supplies fresh air to the reforming cylinder 40d in order to burn the air-fuel mixture in the fuel chamber of the reforming cylinder 40d in a fuel-rich state. A first fuel supply path 29 for supplying the fuel F is connected to the first fuel supply path 29 via a venturi-type mixer 16, and a first fuel flow rate control for controlling the flow rate of the fuel F is connected to the first fuel supply path 29. A valve 15 is provided. On the upstream side of the first fuel flow rate control valve 15 of the first fuel supply path 29, a compressor (not shown) is used to increase the supply pressure of the fuel F to the supercharging pressure at the outlet of the compressor 31 of the air supply main 20. ) Etc. are provided.
Further, the reformed gas passage 28 through which the reformed gas K reformed by the reformed cylinder 40d flows is connected to the reformed cylinder 40d, and is downstream of the reformed gas passage 28. The end is connected to the downstream side of the normal cylinder throttle valve 23 of the air supply main 20. That is, in the third embodiment, all of the reformed gas K is configured to be guided to the normal cylinders 40a, 40b, 40c.
The control device 50 controls the opening degree of the first fuel flow rate control valve 15 so that the excess air ratio of fresh air to the reforming cylinder 40d is smaller than 1. That is, the first fuel supply path 29, the mixer 16, and the first fuel flow rate control valve 15 function as the first fuel supply unit.

The rotation shaft (not shown) of the engine body 40 is provided with a rotation speed sensor for measuring the rotation speed of the rotation shaft (not shown) as an operating state detection unit 41.
Further, the rotation shaft (not shown) of the engine body 40 is provided with a torque measurement sensor for measuring the torque of the rotation shaft as an operating state detection unit 41, and the control device 50 is, for example, a rotation speed sensor. The first fuel flow control valve 15 and the throttle valve for normal cylinder 23 so that the engine output calculated based on the engine speed measured by the torque measurement sensor and the torque measured by the torque measurement sensor becomes the target output. , And control the opening degree of the throttle valve 25 for the reforming cylinder.
All the normal cylinders 40a, 40b, 40c, and the reformed cylinder 40d are provided with an in-cylinder pressure sensor (not shown) for detecting the in-cylinder pressure as an operating state detection unit 41, and the control device 50 , Various controls described later are executed based on the measurement result of the in-cylinder pressure sensor. Further, the control device 50 is configured to be able to acquire the measurement result of the supply air temperature sensor (not shown) that measures the supply air temperature, and various controls to be described later based on the measurement result of the supply air temperature sensor. To execute.

By the way, the engine system 100 according to the embodiment executes the following control in order to improve the thermal efficiency and the exhaust gas properties in the engine system including the normal cylinders 40a, 40b, 40c and the reformed cylinder 40d. ..
The control device 50 executes air excess rate fluctuation control that adjusts the fuel supply amount by the first fuel supply unit and fluctuates and controls the air excess rate in the reforming cylinder 40d within a predetermined range for generating the reformed gas K. In this state, the reformed gas operation for guiding only the reformed gas K as fuel to the normal cylinders 40a, 40b, 40c is executed. That is, in the third embodiment, all the fuel supply amount to all the reforming cylinders 40d (one cylinder in the first embodiment) by the first fuel flow rate control valve 15 as the first fuel supply unit. The reformed gas operation is executed in a state where the fuel ratio, which is the ratio of the total fuel supply amount to the normal cylinders 40a, 40b, 40c (three cylinders in the third embodiment) is maintained at 0.0. Become.
However, at the time of starting, in order to stabilize the operation of the engine, the cell motor assists and the control device 50 temporarily increases the output in the reforming cylinder 40d prior to the reforming gas operation. It is preferable to perform quality cylinder high output operation.

In the air excess rate fluctuation control, when a hydrocarbon gas containing methane as a main component is used as the fuel, the total air excess rate of the normal cylinders 40a, 40b, 40c and the reformed cylinder 40d is 1.0 or more and 1.5. It is preferable to adjust as follows and to control the fluctuation of the excess air ratio in the reformed cylinder 40d in the range of 0.50 or more and 0.90 or less (more preferably 0.55 or more and 0.80 or less).
As a result, the NOx concentration of the exhaust gas E discharged from the normal cylinders 40a, 40b, 40c can be maintained below the target value (for example, 150 ppm at the target value set as a voluntary standard), and the efficiency of the entire system can be maximized. it can.

Further, the control device 50 is based on the stroke volume ratio obtained by dividing the total stroke volume (total displacement) of all the normal cylinders 40a, 40b, 40c into which the reforming gas K is guided by the total stroke volume of the reforming cylinder 40d. , The stroke number ratio control that fluctuates and controls the stroke number ratio, which is a value obtained by dividing the stroke numbers of the normal cylinders 40a, 40b, and 40c by the stroke number of the modified cylinder 40d, is executed by 1 or more. Since the details of the stroke number ratio control are the same as those of the engine system 100 according to the first embodiment, the detailed description thereof will be omitted here.

[Fourth Embodiment]
In the engine system 100 according to the third embodiment, in a single multi-cylinder engine, a configuration example in which the reformed gas K reformed by the reformed cylinder 40d is guided to the normal cylinders 40a, 40b, 40c. Indicated.
As shown in FIG. 8, the engine system 200 according to the fourth embodiment is in addition to the reforming engine 200a having a reforming cylinder 40d for reforming the air-fuel mixture M to generate the reforming gas K. It is configured to include an external output engine 200b having normal cylinders 80a, 80b, 80c, 80d to which the reformed gas K generated by the reforming engine 200a is guided.

In the engine system 200, measurement results of a sensor or the like for detecting the operating state of the external output engine 200b are input, and the hardware group and the software group that control the operation of the external output engine 200b based on the input signal are used. It includes an engine control unit (hereinafter, referred to as a control device 50) that is configured. That is, the engine system 200 according to the fourth embodiment is configured to positively detect the operating state of the external output engine 200b instead of the reforming engine 200a.
In the reformed engine 200a in the engine system 200 according to the fourth embodiment, the normal cylinders 40a, 40b, 40c in the engine system 100 according to the third embodiment are designated as non-remodeling cylinders 40d, 40b, 40c, and the supply for the normal cylinders. The bronchial tubes 20a, 20b, 20c are designated as non-reforming cylinder supply bronze tubes 20a, 20b, 20c.
Further, in the engine system 200 according to the fourth embodiment, the reformed gas K generated in the reformed cylinder 40d is not returned to the air supply main 20 of the reformed engine 200a, that is, the non-reformed cylinder. The reformed gas K is not guided to the air supply branch pipes 20a, 20b, 20c, and the non-reformed cylinders 40d, 40b, 40c to which they are connected.
Further, in the engine system 200 according to the fourth embodiment, the fuel F supplied by the second fuel supply unit is configured to lead to the reformed cylinder 40d in addition to the non-modified cylinders 40d, 40b, 40c. ..
Further, in the engine system 200 according to the fourth embodiment, the fuel F supplied via the second fuel supply path 11, the differential pressure regulator 12, the mixer 14, and the second fuel flow rate control valve 13 is unmodified. In addition to the cylinders 40d, 40b, and 40c, it is configured to lead to the reforming cylinder 40d.
Except for the above points, the modified engine 200a in the engine system 200 according to the fourth embodiment has substantially the same configuration as the engine system 100 according to the third embodiment described above, and has the same control. Execute. Hereinafter, the description will be focused on the configuration and control different from those of the engine system 200 according to the third embodiment, and the detailed description of the same configuration and control may be omitted.

As shown in FIG. 8, the external output engine 200b supplies air from the air supply main 70 to the combustion chambers (not shown) of the normal cylinders 80a, 80b, 80c, 80d via an air supply valve (not shown). By igniting sparks with an ignition plug in a state where the fresh air is compressed by the rise of the piston and burning and expanding it, the piston is pushed down and rotational power is output from the rotating shaft (not shown), and it is generated by combustion. The exhaust gas E is normally pushed out from the combustion chambers of the cylinders 80a, 80b, 80c, and 80d to the exhaust passage through an exhaust valve (not shown) and discharged to the outside.

The air supply main pipe 70 is provided with an air cleaner 71 that purifies the combustion air A.
The rotation shaft (not shown) of the engine body 80 of the external output engine 200b is provided with a rotation speed sensor for measuring the rotation speed of the rotation shaft (not shown) as an operating state detection unit 81, and is a control device. 50 controls the opening degree of the throttle valve 73 based on the measurement result of the rotation speed sensor in order to maintain the engine rotation speed measured by the rotation speed sensor at the target rotation speed.
Further, the rotation shaft (not shown) of the engine body 80 of the external output engine 200b is provided with a torque measurement sensor for measuring the torque of the rotation shaft as an operating state detection unit 81, and the control device 50 is provided with a torque measurement sensor. For example, the first fuel flow control valve 15, usually, so that the engine rotation speed measured by the rotation speed sensor and the engine output calculated based on the torque measured by the torque measurement sensor become the target output. The opening degree of the throttle valve 23 for the cylinder and the throttle valve 73 is controlled.
All the normal cylinders 80a, 80b, 80c, 80d are provided with an in-cylinder pressure sensor for detecting the in-cylinder pressure as an operating state detection unit 81, and the control device 50 is a measurement result of the in-cylinder pressure sensor. Based on the above, various controls described later are executed. Further, the control device 50 is configured to be able to acquire the measurement result of the supply air temperature sensor (not shown) that measures the supply air temperature (the supply air temperature of the external output engine 200b or the supply air temperature of the reforming engine 200a). Based on the measurement result of the supply air temperature sensor, various controls described later are executed.

The air supply main pipe 70 is connected to a plurality of air supply branch pipes 70a, 70b, 70c, 70d that guide the air-fuel mixture M to the normal cylinders 80a, 80b, 80c, 80d on the downstream side of the throttle valve 73.
On the downstream side of the throttle valve 73 in the air supply main 70, and on the upstream side of the plurality of air supply branch pipes 70a, 70b, 70c, 70d, the reformed gas generated by the reforming cylinder 40d of the reforming engine 200a The reformed gas flow path 28 through which K passes is communicated and connected. With this configuration, the reformed gas K flows through all of the above-mentioned air supply branch pipes 70a, 70b, 70c, and 70d at substantially the same flow rate.

In the engine system 200 configured as described above, the following control is executed in order to improve the thermal efficiency and the exhaust gas properties.
The control device 50 executes air excess rate fluctuation control that adjusts the fuel supply amount by the first fuel supply unit and fluctuates and controls the air excess rate in the reforming cylinder 40d within a predetermined range for generating the reformed gas K. In this state, a control device 50 for executing a reformed gas operation that guides only the reformed gas K as fuel to the cylinders 80a, 80b, 80c, and 80d is provided. That is, in the fourth embodiment, the reforming gas operation is executed and the reforming gas K is derived in a state where the fuel ratio described in the third embodiment is maintained at 0.0. The number of strokes of the normal cylinders 80a, 80b, 80c, 80d based on the stroke volume ratio obtained by dividing the total stroke volume (total displacement) of the normal cylinders 80a, 80b, 80c, 80d by the total stroke volume of the modified cylinder 40d. Is divided by the number of strokes of the reforming cylinder 40d, and the stroke number ratio is fluctuated and controlled by 1 or more.
Since the details of the stroke number ratio control are the same as those of the engine system 100 according to the first embodiment, the detailed description thereof will be omitted here.

[Another Embodiment]
(1) In the above-described first and third embodiments, even if the configuration is such that the excess air ratio fluctuation control and the fuel ratio decrease control are not executed and the stroke number ratio control is executed, the normal cylinder and the modified cylinder may be used depending on the operating state. The volume can be balanced with and the pump loss can be reduced.

(2) In the first to fourth embodiments, the total stroke volume, which is the sum of the stroke volumes of all the normal cylinders to which the reformed gas is guided, is more than the total stroke volume, which is the sum of the stroke volumes of all the reformed cylinders. In the case of a large configuration, the number of normal cylinders may be any number as long as it is one or more, and the number of reformed cylinders may be any number as long as it is one or more. Can be demonstrated well.
However, in the engine system 200 according to the second and fourth embodiments, since the reforming engine 200a is an engine for generating the reforming gas K, it is preferable that the number of the reforming cylinders 40d is large. However, the reforming engine 200a may be configured to take out its shaft output and use it for power generation or the like.
Further, in the engine system 200 according to the fourth embodiment, the reforming engine 200a may have only the reforming cylinder. When this configuration is adopted, the fuel F is supplied to the reforming cylinder air supply branch pipe 20d that supplies fresh air to the reforming cylinder 40d via a Venturi type mixer 16 and the Venturi type mixer 16. It is not necessary to provide either the 1 fuel supply path 29 or the 1st fuel flow rate control valve 15 for controlling the flow rate of the fuel F in the 1st fuel supply path 29.
Fuel is supplied to the reformed cylinder and reformed gas K is generated by the proper operation of the second fuel supply path 11, the differential pressure regulator 12, the mixer 14, and the second fuel flow rate control valve 13. become. That is, the second fuel supply path 11, the differential pressure regulator 12, the mixer 14, and the second fuel flow rate control valve 13 function as the first fuel supply unit.
Further, when the configuration is adopted, since all the reformed gas K from the engine 200a is guided to the external output engine 200b, a configuration in which the supercharger 30 is not provided is adopted.

(3) In the third embodiment, the reformed gas flow path 28 connected to the exhaust port of the reformed cylinder 40d has a configuration in which the reformed gas passage 28 is connected to the air supply main 20, and the reformed gas K is supplied. An example of leading to only the normal cylinders 40a, 40b, and 40c is shown.
However, for example, the reformed gas passage 28 is connected to each of the normal cylinder air supply branch pipes 20a, 20b, 20c that supply fresh air to both the reformed cylinders 40a, 40b, 40c and the reformed cylinder 40d. May be adopted.
Further, for example, the reformed gas passage 28 is one or more of the exhaust port of the reformed cylinder 40d and the air supply branch pipes 20a, 20b, 20c for the normal cylinders that supply fresh air to the normal cylinders 40a, 40b, 40c. You may adopt the configuration which is connected to.

(4) In the first to fourth embodiments, the example in which the engine systems 100 and 200 are provided with the supercharger 30 is shown. However, even if the engine system 100 and 200 are not provided with the supercharger 30, the object of the present invention is Is well achieved.
As described above, in the configuration in which the supercharger 30 is not provided, the air supply branch pipe 20d for the reforming cylinder is not boosted to the boost pressure, so that it is supplied to the mixer 16 as the first fuel supply unit. It is not necessary to boost the pressure of the fuel F, and a simple and compact configuration without a compressor or the like for boosting can be achieved. Incidentally, in this case, the pressure of the fuel F supplied from the mixer 16 to the reforming cylinder air supply branch pipe 20d is set to a normal air supply pressure.
Further, in the first to fourth embodiments, the turbocharger type 30 is provided as the supercharger 30, but a supercharger type turbocharger may be used.
Further, in the first to fourth embodiments, the so-called one-stage supercharging example in which a single compressor 31 and a single turbine 32 are provided as the supercharger 30 is shown, but separately, two or more stages are shown. It may be multi-stage supercharging.

(5) In the second and fourth embodiments, a configuration example including a single reforming engine 200a and a single external output engine 200b has been shown, but a configuration including a plurality of reforming engines 200a and an external output It is also possible to adopt a configuration including a plurality of engines 200b.

(6) In the second and fourth embodiments, the control device 50 is shown as a single control device, but the control device for the reforming engine 200a and the control device for the external output engine 200b are separately separated. It is also possible to prepare.

(7) In the second embodiment, a configuration example in which the reformed gas flow path 28 is connected to the air supply main pipe 70 is shown. However, the reformed gas passage 28 is connected to at least one or more of the air supply branch pipes 70a, 70b, 70c, 70d, that is, at least one of the normal cylinders 80a, 80b, 80c, 80d. A configuration in which the reformed gas K is derived may be adopted.

(8) In the first to fourth embodiments, a configuration example for directly measuring the torque of the rotating shaft of the engine has been shown. However, instead of the configuration, for example, the rotating shaft is determined from the throttle opening, boost pressure, and the like. A configuration including a torque estimation means for estimating the torque of the above may be adopted.

(9) In the first to fourth embodiments, the fuel F is city gas 13A, but from the essential meaning of the present invention, it may be a liquid fuel such as gasoline as well as a gas fuel. Absent.

(10) In the above embodiment, the control device 50 has a large stroke volume ratio obtained by dividing the total stroke volume of all the normal cylinders 40a, 40b, 40c into which the reforming gas K is guided by the total stroke volume of the reforming cylinder 40d. The stroke number ratio in the stroke number ratio control may be controlled so as to be large.
Although not shown, for example, each of the air supply branch pipes 20a, 20b, and 20c for a normal cylinder is provided with an on-off valve (not shown), and the open / closed state of the on-off valve can be switched based on a required output or the like. In a configuration in which the total stroke volume of the normal cylinders 40a, 40b, and 40c is switched and the stroke volume ratio can be changed, the stroke number ratio in the stroke number ratio control may be controlled to be larger as the stroke volume ratio is larger.
Further, the number of cylinders of the normal cylinders 40a, 40b and 40c may be configured to be more than 3, and the actual number of cylinders may be controlled by the opening / closing control of the on-off valve described above.

The cylinder volumes of the normal cylinders 40a, 40b, 40c and the modified cylinder 40d may be the same, or even if they are different, the functions of the present invention are satisfactorily exhibited.

(11) In the above embodiment, the configuration in which the control device 50 is provided and the stroke number ratio control is executed is shown.
For example, in the above embodiment, the normal cylinder is not provided with the control device 50, and the normal cylinder is prepared in advance based on the stroke volume ratio obtained by dividing the total stroke volume of all the normal cylinders to which the reforming gas is guided by the total stroke volume of the reforming cylinder. A configuration may be adopted in which the stroke number ratio, which is the value obtained by dividing the stroke number of the above by the stroke number of the reforming cylinder, is 1 or more.

It should be noted that the configuration disclosed in the above embodiment (including another embodiment, the same shall apply hereinafter) can be applied in combination with the configuration disclosed in other embodiments as long as there is no contradiction. The embodiments disclosed in the present specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.

In the configuration in which the reforming gas from the reforming cylinder is guided to the normal cylinder, the engine system of the present invention satisfies the restrictions on the fuel supply amount and the combustion air supply amount based on the stroke volume of the normal cylinder or the reforming cylinder. , It can be effectively used as an engine system capable of further improving the efficiency of the engine system and expanding the upper limit of torque (increasing the upper limit of output).

11: 1st fuel supply path 12: Differential pressure regulator 13: 1st fuel flow control valve 13A: City gas 14: Mixer 15: 2nd fuel flow control valve 16: Mixer 20: Air supply mains 40a, 40b, 40c: Normal cylinder 40d: Remodeling cylinder 50: Control device 80a, 80b, 80c, 80d: Normal cylinder 100: Engine system 200: Engine system 200a: Remodeling engine 200b: External output engine A, A1: Combustion air F: Fuel K : Reform gas M: Air-fuel mixture

Claims (8)

It is provided with at least one reforming cylinder that partially oxidizes at least a part of the air-fuel mixture containing fuel and combustion air to reform it into a reforming gas containing a combustion-promoting gas having a faster combustion rate than the fuel. Equipped with a normal cylinder in addition to the reformed cylinder
A first fuel supply unit for supplying fuel guided to the reforming cylinder is provided.
In an engine system configured to guide the reformed gas reformed in the reformed cylinder to at least the normal cylinder.
The total stroke volume, which is the sum of the stroke volumes of all the normal cylinders to which the reformed gas is guided, is larger than the total stroke volume, which is the sum of the stroke volumes of all the reformed cylinders.
The number of strokes of the normal cylinder is the number of strokes of the reforming cylinder based on the stroke volume ratio obtained by dividing the total stroke volume of all the normal cylinders to which the reforming gas is guided by the total stroke volume of the reforming cylinder. An engine system in which the stroke number ratio, which is the value divided by, is 1 or more. It is provided with at least one reforming cylinder that partially oxidizes at least a part of the air-fuel mixture containing fuel and combustion air to reform it into a reforming gas containing a combustion-promoting gas having a faster combustion rate than the fuel. Equipped with a normal cylinder in addition to the reformed cylinder
A first fuel supply unit for supplying fuel guided to the reforming cylinder is provided.
In an engine system configured to guide the reformed gas reformed in the reformed cylinder to at least the normal cylinder.
The total stroke volume, which is the sum of the stroke volumes of all the normal cylinders to which the reformed gas is guided, is larger than the total stroke volume, which is the sum of the stroke volumes of all the reformed cylinders.
The number of strokes of the normal cylinder is the number of strokes of the reforming cylinder based on the stroke volume ratio obtained by dividing the total stroke volume of all the normal cylinders to which the reforming gas is guided by the total stroke volume of the reforming cylinder. An engine system including a control device capable of performing stroke number ratio control that fluctuates and controls the stroke number ratio, which is a value divided by. A modification equipped with at least one reforming cylinder that partially oxidizes at least a part of the air-fuel mixture containing fuel and combustion air to reform it into a reformed gas containing a combustion-promoting gas whose combustion speed is faster than that of fuel. It has a quality engine and an external output engine equipped with a normal cylinder in addition to the reformed cylinder.
A first fuel supply unit for supplying fuel guided to the reforming cylinder is provided.
In an engine system configured to guide the reformed gas reformed in the reformed cylinder to at least the normal cylinder.
The total stroke volume, which is the sum of the stroke volumes of all the normal cylinders to which the reformed gas is guided, is larger than the total stroke volume, which is the sum of the stroke volumes of all the reformed cylinders.
The number of strokes of the normal cylinder is the number of strokes of the reforming cylinder based on the stroke volume ratio obtained by dividing the total stroke volume of all the normal cylinders to which the reforming gas is guided by the total stroke volume of the reforming cylinder. An engine system including a control device capable of performing stroke number ratio control that fluctuates and controls the stroke number ratio, which is a value divided by. In the control device, the larger the stroke volume ratio obtained by dividing the total stroke volume of all the normal cylinders to which the reforming gas is guided by the total stroke volume of the reforming cylinder, the more the stroke number in the stroke number ratio control. The engine system according to claim 2 or 3, wherein the ratio is largely controlled. At least a second fuel supply unit that supplies fuel guided to the normal cylinder and a first fuel supply unit that supplies fuel guided to the reforming cylinder are separately provided.
The control device executes air excess rate fluctuation control that adjusts the fuel supply amount by the first fuel supply unit and fluctuates the air excess rate in the reforming cylinder within a predetermined range for generating reformed gas. In the state of
Fuel ratio reduction that reduces the fuel ratio, which is the ratio of the total fuel supply amount to all the normal cylinders by the second fuel supply unit to the total fuel supply amount to all the reforming cylinders by the first fuel supply unit. The engine system according to any one of claims 2 to 4, which executes control. The engine system according to claim 5, wherein the control device controls the fuel ratio to 0.0 or more and 0.50 or less by the fuel ratio decrease control while executing the air excess rate fluctuation control. The control device adjusts the amount of fuel supplied by the first fuel supply unit, the amount of air supplied to the reformed cylinder, or both to generate a reformed gas at an excess air ratio in the reformed cylinder. Any one of claims 2 to 4 for executing a reformed gas operation that guides only the reformed gas as the fuel to the normal cylinder while executing the air excess rate fluctuation control that controls the fluctuation within a predetermined range. The engine system described in the section. The engine system according to claim 7, wherein the control device executes a reformed cylinder high output operation for temporarily increasing the output in the reformed cylinder prior to the reformed gas operation at the time of starting.