JP3999767B2 - Two-fluid injection internal combustion engine and method of operating the same - Google Patents

Description

  The present invention is mainly applied to a two-fluid injection internal combustion engine (for example, a gas engine or a diesel engine), and a fuel injection valve that injects fuel from the fuel injection device into the cylinder, and steam from the steam injection device into the cylinder. The present invention relates to a two-fluid injection internal combustion engine and a method for operating the same.

In an internal combustion engine, it is well known that when fuel is injected into a cylinder from a fuel injection valve before top dead center and steam is injected during a heat receiving period after the fuel injection, work amount and thermal efficiency are increased. As one of such techniques, there is a technique disclosed in Japanese Patent Application Laid-Open No. 2002-54510.
In such a technique, a steam line that is connected to an air supply pipe so that steam can be sucked into the air supply port, and a valve opening adjustment signal that is interposed in the steam line is input to vary the amount of steam injected. Calculates the amount of water required for the flow rate adjustment valve and the humidity of the air supplied to the air supply pipe to reach the target absolute humidity, and outputs a valve opening adjustment signal for injecting the required amount of water to the flow rate adjustment valve. The control means is provided so that NOx is suppressed to a low level throughout the year while suppressing an increase in the fuel consumption rate, and it is not necessary to perform engine adjustments such as the beginning of every season.

JP 2002-54510 A

In an internal combustion engine, when steam is injected during the heat receiving period after fuel injection before top dead center, the work volume increases and the thermal efficiency increases, while the maximum pressure in the cylinder does not exceed the allowable value. Even if it carries out like this, after the end of the heat receiving period, the in-cylinder maximum temperature is shifted to the high temperature side, and when the steam injection is terminated, the in-cylinder pressure / temperature decrease curve in the expansion stroke is shifted to the higher side, and the expansion stroke ends. The in-cylinder temperature at the time is shifted to the high temperature side.
For this reason, the amount of NOx (nitrogen oxide) generated increases due to the rise in in-cylinder temperature accompanying steam injection during the heat receiving period, and the thermal stress of the combustion chamber constituent member rises, making it difficult to maintain durability. .

  However, in the technique of Patent Document 1, a valve opening degree adjustment signal for calculating the amount of water necessary for the humidity of the air supplied to the air supply pipe to reach the target absolute humidity and injecting the necessary amount of water is provided. It is only configured to output to the flow rate regulating valve of the steam line, and no countermeasure is taken against the temperature increase in the cylinder due to the steam injection as described above.

  In view of the problems of the conventional technology, the present invention reduces the amount of NOx (nitrogen oxide) generated by lowering the in-cylinder temperature while maintaining the increase in work amount and the increase in thermal efficiency due to the injection of steam and the like. An object of the present invention is to provide a fluid injection type internal combustion engine capable of maintaining the durability of a combustion chamber component.

The present invention achieves such an object, and is provided with a fuel injection valve that injects fuel from the fuel injection device into the cylinder and a steam injection valve that injects steam from the steam injection device into the cylinder. In the fluid injection type internal combustion engine, the steam is injected from the steam injection valve before the end of the heat receiving period after fuel injection from the fuel injection valve into the cylinder and twice from the end of the heat receiving period to the expansion stroke. A control device for controlling the steam injection device, and under the control of the control device, the steam is injected from the steam injection valve before the end of the heat receiving period in the cylinder through the steam injection device, and further after the end of the heat receiving period configured to perform the steam injection, the increase in the required amount of work in the expansion stroke cylinder maximum pressure (Pmax) and the in-cylinder maximum temperature (Tmax) are both below the allowable value is obtained The target heat receiving rate mode is set, and the fuel injection condition from the fuel injection valve and the steam injection condition from the steam injection valve are controlled so that the actual heat receiving rate mode becomes the target heat receiving rate mode. It is characterized by.

As a method of operating the two-fluid injection internal combustion engine, a fuel injection valve for injecting fuel from the fuel injection device into the cylinder and a steam injection valve for injecting steam from the steam injection device into the cylinder are provided. In the operating method of the two-fluid injection internal combustion engine, the fuel is injected into the cylinder from the fuel injection valve before the top dead center of the internal combustion engine, and the fuel expands before and after the end of the heat receiving period after the fuel injection. Steam is injected from the steam injection valve twice during the stroke, and the maximum work pressure in the expansion stroke is obtained when both the maximum cylinder pressure (Pmax) and the maximum cylinder temperature (Tmax) are less than the allowable values. The target heat receiving rate mode is set, and the fuel injection condition from the fuel injection valve and the steam injection condition from the steam injection valve are controlled so that the actual heat receiving rate mode becomes the target heat receiving rate mode. Suggest method of operating a two-fluid injection internal combustion engine according to claim.

In this invention, specifically, the engine is operated by performing the following control by the control device.
That is, an actual heat receiving rate mode in the cylinder is calculated based on the in-cylinder pressure detection value from the in-cylinder pressure detection means and the in-cylinder temperature detection value from the in-cylinder temperature detection means .

Further, the target heat receiving rate mode is set based on set values of the fuel injection amount and fuel injection timing of the engine, and the set values of steam injection amount and steam injection timing .

According to this invention, the fuel is injected into the cylinder from the fuel injection valve before the top dead center of the engine, and the steam is injected from the steam injection valve before the end of the heat receiving period after the fuel injection, preferably before the top dead center. Further, by injecting steam from the steam injection valve in the expansion stroke after the end of the heat receiving period, the work amount in the expansion stroke increases, the engine output increases, and the thermal efficiency of the engine increases.
In addition, due to the heat absorption effect of the steam accompanying the steam injection in the expansion stroke from the end of the heat receiving period, the in-cylinder temperature is lower than in the prior art that does not perform the steam injection in the expansion stroke, and NOx (nitrogen oxide) Generation | occurrence | production can be suppressed and the thermal stress of a combustion chamber structural member can fall and durability can be hold | maintained.

  In addition, the target heat receiving rate mode, which is the optimum value of the heat receiving rate mode during the heat receiving period, is set for both the preset fuel injection amount and fuel injection timing, and the steam injection amount and steam injection timing. Based on the comparison result between the detected heat reception rate mode calculated based on the pressure detection value and the in-cylinder temperature detection value and the target heat reception rate mode, the fuel injection conditions from the fuel injection valve, that is, the fuel injection amount, the fuel injection timing, and the steam injection valve Since the actual heat receiving rate mode is controlled so as to match the target heat receiving rate mode by changing both the steam injection conditions, i.e., the steam injection amount and the steam injection timing, from all over the engine operating range. Combustion in the optimum heat receiving rate mode can be continued.

  Further, according to the invention, the target heat receiving rate mode set as described above is configured such that the in-cylinder maximum pressure (Pmax) is an allowable value and the in-cylinder maximum temperature (Tmax) or the allowable value of the combustion gas temperature such as the exhaust temperature. The target heat receiving rate mode is corrected so that the in-cylinder maximum pressure is less than or equal to an allowable value and the combustion gas temperature is less than or equal to an allowable value, and the target heat receiving rate mode is set to the target heat receiving rate. Since the mode is changed, the combustion in the heat receiving rate mode in which the maximum in-cylinder pressure is always kept below the allowable value and the combustion gas temperature can be kept below the allowable value can be continued.

  Therefore, according to this invention, the fuel is injected into the cylinder from the fuel injection valve before the top dead center of the engine, before the end of the heat receiving period after fuel injection, and twice from the end of the heat receiving period to the expansion stroke. By injecting steam from the valve, the amount of work in the expansion stroke is increased, the engine output is increased, and the thermal efficiency of the engine can be increased.

  Further, the heat receiving rate mode during the heat receiving period is controlled by both the fuel injection amount and the fuel injection timing, and the steam injection amount and the steam injection timing, and the heat receiving rate mode is set so that the in-cylinder maximum pressure is less than the allowable value. In addition, the combustion gas temperature is corrected to be below the allowable value, so by controlling the actual heat receiving rate mode to match the target heat receiving rate mode, the optimum heat receiving rate mode is always maintained in the entire engine operating range. Combustion can be continued, and stable operation can be continued in which the in-cylinder maximum pressure and the combustion gas temperature are always kept below the allowable values and the durability of the combustion chamber constituent members is maintained.

Moreover, in this invention, it is also possible to comprise so that the said vapor | steam injection may be performed by the following two means.
(1) Steam injection from the steam injection valve is continuously performed from before the end of the heat receiving period to after the end of the heat receiving period.
(2) Steam injection from the steam injection valve is performed a plurality of times before the end of the heat receiving period, and further a plurality of times from the end of the heat receiving period to the expansion stroke.

In this invention, preferably, the fuel injection device and the fuel injection valve, and the steam injection device and the steam injection valve are configured in a proportional control valve system in which the fuel injection amount or the steam injection amount changes proportionally.
With this configuration, the fuel injection amount from the fuel injection valve and the steam injection amount from the steam injection valve can be continuously changed in proportion to the time change, so that the in-cylinder pressure detection value and the in-cylinder temperature By continuously controlling the fuel injection amount and fuel injection timing, and the steam injection amount and steam injection timing based on the detected value of the combustion gas temperature including the detected value, the heat receiving rate mode in the cylinder can be controlled with high accuracy. .

In this invention, supercritical water can be used instead of the steam.
In this way, generation of NOx (nitrogen oxide), soot and the like can be suppressed by vigorous reactivity in the cylinder of supercritical water.

According to the present invention, fuel is injected into the cylinder from the fuel injection valve before the top dead center of the engine, before the end of the heat receiving period after fuel injection and twice from the end of the heat receiving period to the expansion stroke, from the steam injection valve. By injecting the steam, the work amount in the expansion stroke is increased, the engine output is increased, and the thermal efficiency of the engine can be increased.
In addition, due to the heat absorption effect of the injected steam in the expansion stroke from the end of the heat receiving period, the in-cylinder temperature is lower than in the prior art that does not perform the steam injection in the expansion stroke, and generation of NOx (nitrogen oxide) can be suppressed At the same time, the thermal stress of the combustion chamber constituent member is lowered, and the durability can be maintained.

Further, the heat receiving rate mode during the heat receiving period is controlled by both the fuel injection amount and the fuel injection timing, and the steam injection amount and the steam injection timing, and the heat receiving rate mode is set so that the maximum in-cylinder pressure is less than the allowable value. In addition, since the combustion gas temperature is corrected so that it falls below the allowable value, combustion in the optimal heat receiving rate mode is always performed in the entire engine operating range by controlling the actual heat receiving rate mode to match the target heat receiving rate mode. Can be continued, and the stable operation in which the in-cylinder maximum pressure and the combustion gas temperature are always kept below the allowable values and the durability of the combustion chamber constituent members is maintained can be continued.
Moreover, if supercritical water is used instead of the steam, generation of NOx (nitrogen oxide), soot and the like can be suppressed due to active reactivity in the cylinder of the supercritical water.

  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 a system diagram showing the overall configuration of a fuel / steam injection type 4-cycle diesel engine according to an embodiment of the present invention. FIG. 2 is a control block diagram in the embodiment, and FIGS. 3A and 3B are diagrams for explaining the operation in the embodiment. FIG. 4 is a partial cross-sectional view showing the structure of the fuel injection device and the fuel injection valve in the embodiment.

  In FIG. 1 showing the overall configuration of a fuel / steam injection type internal combustion engine, 100 is an engine (internal combustion engine), 101 is a plurality of cylinders of the engine 100 (only one cylinder is shown in this figure), and 102 is exhaust A turbocharger composed of a turbine 102a and a compressor 102b, 104 is an air supply cooler, 103 is an exhaust pipe, 105 is an air supply pipe, and exhaust gas from the engine 100 passes through the exhaust pipe 103 and is an exhaust turbine of the supercharger 102 102a is driven, and the high-pressure and high-temperature air (supply air) pressurized by the compressor 102b of the supercharger 102 is cooled and cooled by the supply air cooler 104, passes through the supply air pipe 105, and is supplied to the cylinder 101 of the engine 100. It is designed to be supplied inside. Reference numeral 106 denotes a generator that is directly connected to the engine 100.

6 is a fuel injection device into which pressurized high-pressure fuel is introduced, 4 is a fuel injection valve (detailed structure will be described later), and the fuel whose fuel injection amount and injection timing are controlled in the fuel injection device 6 is fuel. The fuel is injected into the cylinder 101 from the injection valve 4.
Reference numeral 10 denotes a water pump, and 8 denotes a heat exchanger that generates steam from the water supplied by the water pump 10. The heat exchanger 8 is introduced from the water supplied from the water pump 10 and the exhaust pipe 103. The exhaust gas after driving the exhaust turbine 102a of the supercharger 102 is heat-exchanged to heat the water and generate steam. 9 is a separator for separating and removing harmful solids in the exhaust gas at the outlet of the heat exchanger 8, and the exhaust gas purified by the separator 9 is released into the atmosphere.

7 is a steam injection device to which the high-pressure steam generated by the heat exchanger 8 is introduced, and 5 is a steam injection valve (detailed structure will be described later). In the steam injection device 7, the steam injection amount and the injection timing are determined. Controlled steam is injected into the cylinder 101 from the steam injection valve 5.
1 is a control device that performs computation and control described later, 2 is an in-cylinder pressure sensor that detects gas pressure (in-cylinder pressure) in the cylinder 101, and 3 is an exhaust temperature that detects the temperature of exhaust gas in the exhaust pipe 103. A sensor 30 is a load detector that detects a load (engine output) of the engine 100. The detected value of the in-cylinder pressure from the in-cylinder pressure sensor 2, the detected value of the exhaust temperature from the exhaust temperature sensor, and the load The detected value of the engine load (engine output) from the detector 30 is input to the control device 1.

As the fuel injection device 6 and the fuel injection valve 4, and the steam injection device 7 and the steam injection valve 5, it is preferable to use a proportional control injection device having a giant magnetostrictive actuator as shown in FIG.
FIG. 4 shows a proportional control injection device provided with a giant magnetostrictive actuator applied to the fuel injection device 6 and the fuel injection valve 4. In addition, the same structure as FIG. 4 is applicable also to the said steam injection apparatus 7 and the steam injection valve 5. FIG.

In FIG. 4, 014 is a fuel accumulator pipe (fuel common rail), 015 is a high-pressure fuel pump, 016 is a fuel tank, and 017 is a fuel pipe. The fuel in the fuel tank 016 is pressurized to a high pressure by the fuel pump 015. The fuel is stored in the fuel accumulating pipe 014 through the fuel pipe 017 and accumulated in the fuel accumulating pipe 014.
022 is a common oil pipe, 023 is a hydraulic oil pump, 025 is a hydraulic oil tank, 024 is a hydraulic oil pipe, and the hydraulic oil in the hydraulic oil tank 025 is sent to the common oil pipe 022 through the hydraulic oil pipe 024 by the hydraulic oil pump 023. The oil pipe 022 is accommodated.

A fuel injection valve 4 is configured as follows.
05 is an injection valve main body, 04 is a plurality of injection holes perforated at the tip of the injection valve main body 05, 06 is an oil reservoir communicating with the injection hole 04, 02 is reciprocatingly slid into the injection valve main body 05 A needle valve 09, which can be fitted, is a needle valve chamber formed in the injection valve body 05 with the outer peripheral surface of the needle valve 02 facing, and the high pressure fuel from the fuel accumulating pipe 014 is supplied to the fuel inlet 08. After that, the needle valve chamber 09 is introduced.
A conical seat portion 02a is formed at the tip of the needle valve 02, and the seat portion 02a is attached to and detached from a valve seat 05a formed in the injection valve body 05, so that the needle valve chamber 09 and the oil seat The reservoir 06 and the injection hole 04 are communicated and blocked.

Reference numeral 013 denotes an oil chamber formed on the injection valve body 05 with the needle valve chamber 09 and the partition wall 0013 separated from each other. The outer peripheral surface of the main body portion 02b, which is the large diameter portion of the needle valve 02, faces from the common oil pipe 022. The hydraulic oil is introduced into the oil chamber 013 through the hydraulic oil inlet 027.
Reference numeral 019 denotes a pilot control chamber formed in the injection valve body 05 with the oil chamber 013 and the partition wall 011 separated from each other. The needle valve 02 has an end surface 018 opposite to the seat portion 02a.
A control notch portion 012 having a width W over a certain length is formed on the outer peripheral surface of the main body portion 02b of the needle valve 02, and the needle valve due to a differential pressure between the oil chamber 013 and the needle valve chamber 9 is formed. The axial movement of 02 allows the oil chamber 013 and the pilot control chamber 019 to communicate with each other through the control cutout portion 012.

  Reference numeral 031 denotes a pilot valve that opens and closes a pilot oil outlet hole 021 of the pilot control chamber 019 that is perforated at the end of the injection valve main body 05. That is, the pilot valve 031 opens and closes the pilot oil outlet hole 021 of the pilot control chamber 019 by attaching and detaching a flat contact surface to the valve seat surface 05c formed at the end of the injection valve body 05. It is supposed to be.

030 is a giant magnetostrictive actuator, which is configured as follows.
033 is a magnet (electromagnet), 032 is a giant magnetostrictive material that is displaced by magnetostriction, and is temporarily fixed to the support portion at the base of the pilot valve 031. When the magnet 033 is energized, the giant magnetostrictive material 032 is axially moved. The pilot valve 031 is caused to reciprocate by being displaced to. Reference numeral 034 denotes a spring interposed between the support portion of the pilot valve 031 and the main body portion 035 of the actuator, and is biased in the direction in which the pilot valve 031 is closed.
The basic configuration of the giant magnetostrictive actuator 030 is known per se. In this embodiment, the pilot valve 031 is connected to the giant magnetostrictive actuator 030 and is driven to open and close.

Next, the operation of this embodiment will be described based on the control block diagram of FIG. 2 and the action explanatory diagrams of FIGS. 3 (A) and 3 (B).
The detected value of the in-cylinder pressure from the in-cylinder pressure sensor 2 is input to the in-cylinder temperature calculation unit 11 and the heat receiving rate calculation unit 12 of the control device 1. The in-cylinder temperature calculation unit 11 calculates the in-cylinder temperature based on the detected value of the in-cylinder pressure and inputs it to the heat receiving rate calculation unit 12 (the in-cylinder temperature may be directly detected).
In the heat receiving rate calculation unit 12, a heat receiving rate mode is calculated based on the time variation of the in-cylinder pressure and the in-cylinder temperature and is input to the heat receiving rate correction unit 22.

Reference numeral 13 denotes a fuel injection amount mode setting unit, and reference numeral 14 denotes a fuel injection timing setting unit. A fuel injection amount mode in which the heat reception rate mode in the cylinder after the fuel injection and steam injection described later becomes a target heat reception rate mode described later. The fuel injection timing is set. 15 is a steam injection amount setting unit, and 16 is a steam injection timing setting unit. The steam injection amount mode and the steam injection are such that the heat receiving rate mode in the cylinder after the fuel injection and the steam injection becomes a target heat receiving rate mode to be described later. The time is set.
Reference numeral 17 denotes a target heat receiving rate setting unit, which is a target heat receiving rate calculated based on the fuel injection amount mode setting unit 13 and the fuel injection timing setting unit 14, and the steam injection amount mode setting unit 15 and the steam injection timing setting unit 16. As will be described later, a heat receiving rate mode is set so that the required amount of work increase in the expansion stroke can be obtained.

That is, as shown in FIGS. 3A and 3B, in this embodiment, fuel is injected from the fuel injection valve 4 into the cylinder 101 at θ ₁ before the top dead center (TDC) of the engine 100. the steam from the steam injection valve 5 to the theta ₂ before or heat during periods heat period starting from S ₁ of FIG. after fuel injection into the cylinder by injection as Gs _1, the end of receiving heat period S _{22 (or} The fuel injection amount mode setting unit 13 and the fuel injection timing setting unit 14 are provided with the fuel injection amount mode and the fuel injection timing setting unit 14 so that the _second steam injection Gs ₂ is performed from the steam injection valve 5 at θ ₃ from θ ₂₂ ) to the expansion stroke. A fuel injection timing is set, and a steam injection amount mode and a steam injection timing are set in the steam injection amount setting unit 15 and the steam injection timing setting unit 16. In FIG. 3A, W ₃ is blowdown energy and W ₄ is turbine work.
The set value of the target heat receiving rate mode in the target heat receiving rate setting unit 17 is input to the target heat receiving rate correction unit 18.

  Reference numeral 19 denotes an allowable Pmax setting unit, which is set with an allowable value of the in-cylinder maximum pressure (Pmax) corresponding to the engine load input from the load detector 30. Reference numeral 20 denotes an allowable Tmax setting unit, which is set as an allowable value of the in-cylinder maximum temperature (Tmax) corresponding to the engine load input from the load detector 30. Reference numeral 21 denotes an allowable exhaust temperature setting unit, which is set with an allowable value of the exhaust temperature corresponding to the engine load input from the load detector 30. Allowable value of in-cylinder maximum pressure (Pmax) from the allowable Pmax setting unit 19, allowable value of in-cylinder maximum temperature (Tmax) from the allowable Tmax setting unit 20, and exhaust temperature from the allowable exhaust temperature setting unit 20 Is input to the target heat rate correction unit 18.

In the target heat receiving rate correction unit 18, the set value of the target heat receiving rate mode from the target heat receiving rate setting unit 17 is set to the allowable value of the in-cylinder maximum pressure (Pmax) and the allowable value of the in-cylinder maximum temperature (Tmax). Then, the allowable value of the exhaust temperature is taken in and corrected, and the optimum value of the corrected target heat receiving rate mode, that is, the heat receiving rate mode is calculated and input to the heat receiving rate correcting unit 22.
The heat receiving rate correction unit 22 compares the calculated heat receiving rate mode calculated based on the time change of the in-cylinder pressure and the in-cylinder temperature with the heat receiving rate calculating unit 12 and the exhaust target temperature. Correction based on the detection value of the exhaust temperature from the sensor, and based on the comparison result and the correction result, the fuel injection amount mode and the adjustment amount of the fuel injection timing, the steam injection amount mode and the steam so as to be the corrected target heat receiving rate mode. The adjustment amount of the injection timing is calculated (23, 24) and output to the fuel injection device 6 and the steam injection device 7, respectively.
In the fuel injection valve 4, fuel injection is performed in the fuel injection amount mode and the fuel injection timing according to the adjustment amount from the fuel injection device 6. In the steam injection valve 5, steam injection is performed in the steam injection amount mode and the steam injection timing according to the adjustment amount from the steam injection device 7.

Moreover, the said control apparatus 1 can also be controlled to perform the steam injection from the steam injection valve 5 by the following two means.
(1) performing the steam injection from the steam injection valve 5, continuing from the previous heat period end _{S 22} (or theta ₂₂₎ until after the heat-receiving period end _{S 22} (or theta _22).
(2) the steam injection from the steam injection valve 5, further performed a plurality of times more than once prior to the heat-receiving period end _{S 22} (or theta _22), and from said heat receiving period end _{S 22} (or theta ₂₂₎ toward the expansion stroke.

According to this embodiment, the fuel injected from the fuel injection valve 4 before the top dead center of the engine 100 in the cylinder 101, before the heat receiving period at the end S ₂₂ after fuel injection, preferably before top dead center in after having injected steam from the steam injection valve 5, further by performing the steam injection valve 5 second steam injection toward the expansion stroke from the heat receiving period at the end of S _22, (W from W ₀ shown in FIG. 3 (a) ₀ + W ₁ ), the work amount W in the expansion stroke increases, the engine output increases, and the thermal efficiency of the engine increases.
Further, by the heat absorbing action of steam with the steam injection in the expansion stroke from the heat receiving period at the end of S _22, cylinder temperature is lowered in the expansion stroke at the end S ₃₂ than the prior art that does not perform steam injection in such expansion stroke And generation | occurrence | production of NOx (nitrogen oxide) can be suppressed, and the thermal stress of a combustion chamber structural member falls.

  In addition, the target heat receiving rate mode, which is the optimum value of the heat receiving rate mode during the heat receiving period, is set for both the preset fuel injection amount and fuel injection timing, and the steam injection amount and steam injection timing. Based on the comparison result between the detected heat receiving rate mode calculated based on the detected pressure value and the in-cylinder temperature detected value and the target received heat rate mode, the fuel injection condition from the fuel injection valve 4, that is, the fuel injection amount, the fuel injection timing, and the steam injection The steam injection condition from the valve 5, that is, the steam injection amount and the steam injection timing are both changed in association with each other, and the actual heat receiving rate mode is controlled to match the target heat receiving rate mode. Combustion in the optimum heat receiving rate mode can be continued at all times.

  Further, according to this embodiment, the target heat receiving rate mode set as described above is taken in the allowable value of the in-cylinder maximum pressure (Pmax) and the allowable value of the in-cylinder maximum temperature (Tmax) or the allowable value of the exhaust temperature. The target heat receiving rate mode is corrected so that the in-cylinder maximum pressure is less than or equal to an allowable value and the in-cylinder maximum temperature or exhaust temperature is less than or equal to an allowable value. Since it has been changed to the target heat rate mode, the heat rate mode is such that the maximum in-cylinder pressure is always kept below the allowable value and the combustion gas temperature such as the maximum in-cylinder temperature and exhaust temperature can be kept below the allowable value. Can continue burning.

Also, supercritical water can be used in place of the steam in the above embodiment. Also in this case, it is possible to use an injection system similar to the fuel injection device and the fuel injection valve shown in FIG.
According to such a system using supercritical water, the effect of suppressing the generation of NOx (nitrogen oxide), soot, etc. is increased due to the active reactivity in the cylinder of supercritical water.
In addition, although the said Example has shown about the case where this invention is applied to a 4-cycle diesel engine, this invention is applicable to a 2-cycle diesel engine, a gas engine, etc., without being limited to this.

  According to the present invention, while maintaining the increase in work amount and the increase in thermal efficiency due to the injection of steam or supercritical water, the in-cylinder temperature is lowered to reduce the generation amount of NOx (nitrogen oxide), and the combustion chamber It is possible to provide a two-fluid injection internal combustion engine that can maintain the durability of the constituent members.

1 is a system diagram showing an overall configuration of a fuel / steam injection type internal combustion engine according to an embodiment of the present invention. It is a control block diagram in the embodiment. (A), (B) is a diagram for effect | action description in the said Example. It is a partial cross section figure which shows the structure of the fuel-injection apparatus and fuel-injection valve in the said Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control apparatus 2 In-cylinder pressure sensor 3 Exhaust temperature sensor 4 Fuel injection valve 5 Steam injection valve 6 Fuel injection apparatus 7 Steam injection apparatus 8 Heat exchanger 30 Load detector 100 Engine (internal combustion engine)
101 cylinder 102 supercharger 103 exhaust pipe 105 air supply pipe 106 generator

Claims (13)

In a two-fluid injection internal combustion engine comprising a fuel injection valve for injecting fuel from a fuel injection device into a cylinder and a steam injection valve for injecting steam from the steam injection device into the cylinder, the fuel injection valve A control device for controlling the steam injection device to inject steam from the steam injection valve twice before the end of the heat receiving period after fuel injection into the cylinder and from the end of the heat receiving period to the expansion stroke; Under the control of the control device, the steam is injected from the steam injection valve before the end of the heat receiving period in the cylinder via the steam injection device, and the second steam injection is performed after the end of the heat receiving period . A target heat rate mode is set so that the maximum pressure (Pmax) and the in-cylinder maximum temperature (Tmax) are both below the allowable values and the required work volume can be increased in the expansion stroke. As the heat receiving rate mode is the target heat rate mode, the fuel injection condition and 2 a fluid jet, characterized by comprising configured to control steam injection condition from the steam injection valves from the fuel injection valve Internal combustion engine. In the two-fluid injection internal combustion engine comprising a fuel injection valve for injecting fuel from the fuel injection device into the cylinder and a steam injection valve for injecting steam from the steam injection device into the cylinder, the steam injection valve From the end of the heat receiving period until after the end of the heat receiving period, and the maximum in-cylinder pressure (Pmax) and the maximum in-cylinder temperature (Tmax) are less than the allowable values. A target heat receiving rate mode is set so that the required work amount can be increased in the expansion stroke, and the fuel injection conditions and steam injection from the fuel injection valve are set so that the actual heat receiving rate mode becomes the target heat receiving rate mode. A two-fluid injection internal combustion engine configured to control a steam injection condition from a valve . In the two-fluid injection internal combustion engine comprising a fuel injection valve for injecting fuel from the fuel injection device into the cylinder and a steam injection valve for injecting steam from the steam injection device into the cylinder, the steam injection valve From the end of the heat receiving period and multiple times from the end of the heat receiving period to the expansion stroke, both the maximum in-cylinder pressure (Pmax) and the maximum in-cylinder temperature (Tmax) are allowed The target heat receiving rate mode is set so that the required work amount can be increased in the expansion stroke below the value, and the fuel injection from the fuel injection valve is set so that the actual heat receiving rate mode becomes the target heat receiving rate mode. A two-fluid injection internal combustion engine configured to control conditions and steam injection conditions from a steam injection valve . In-cylinder pressure detection means for detecting an in-cylinder pressure of the internal combustion engine (hereinafter also referred to as an engine) and in-cylinder temperature detection means for detecting an in-cylinder temperature of the engine, the control device includes the in-cylinder pressure The in-cylinder pressure detection value from the detection means and the in-cylinder temperature detection value from the in-cylinder temperature detection means are configured to calculate the actual heat receiving rate mode in the cylinder. The two-fluid injection internal combustion engine according to any one of 1 to 3 . The control device is configured to set the target heat receiving rate mode based on a set value of the fuel injection amount and fuel injection timing of the engine and a set value of the steam injection amount and steam injection timing. The two-fluid injection internal combustion engine according to any one of claims 1 to 3 . Engine load detecting means for detecting the load or output of the engine is provided, and the control device determines the allowable value of the in-cylinder maximum pressure and the allowable value of the combustion gas temperature based on the detected engine load value from the engine load detecting means. The two-fluid injection internal combustion engine according to any one of claims 1 to 3, wherein the internal combustion engine is configured to be set . The fuel injection device and the fuel injection valve, and the steam injection device and the steam injection valve are configured in a proportional control valve system in which a fuel injection amount or a steam injection amount changes proportionally. The two-fluid injection internal combustion engine according to any one of claims 3 to 4 . The two-fluid injection internal combustion engine according to any one of claims 1 to 7, wherein supercritical water is used instead of the steam . In the method of operating a two-fluid injection internal combustion engine comprising a fuel injection valve for injecting fuel from a fuel injection device into a cylinder and a steam injection valve for injecting steam from the steam injection device into the cylinder, Before the top dead center of the internal combustion engine, fuel is injected into the cylinder from the fuel injection valve, and before the end of the heat receiving period after the fuel injection and twice from the end of the heat receiving period to the expansion stroke, the steam is injected from the steam injection valve. The target heat-receiving rate mode is set such that the maximum in-cylinder pressure (Pmax) and the in-cylinder maximum temperature (Tmax) are less than the permissible values and the required work amount is increased in the expansion stroke. A method of operating a two-fluid injection internal combustion engine , wherein the fuel injection condition from the fuel injection valve and the steam injection condition from the steam injection valve are controlled so that the rate mode becomes the target heat receiving rate mode . The in-cylinder pressure and in-cylinder temperature of the engine are detected, and the actual heat receiving rate mode in the cylinder is calculated based on the in-cylinder pressure detection value and the in-cylinder temperature detection value. A method for operating a two-fluid injection internal combustion engine. 10. The two-fluid injection internal combustion engine according to claim 9, wherein the target heat receiving rate mode is set based on a set value of an engine fuel injection amount and a fuel injection timing, and a set value of a steam injection amount and a steam injection timing. How the engine operates. 10. The two-fluid injection according to claim 9, wherein an engine load or an engine output is detected, and an allowable value of the in-cylinder maximum pressure and an allowable value of combustion gas temperature are set based on the detected value of the engine load. Of operating an internal combustion engine. The method of operating a two-fluid injection internal combustion engine according to any one of claims 9 to 12, wherein supercritical water is used instead of the steam .

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