Control device, gas engine, control method, and program
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- MITSUBISHI HEAVY IND ENGINE & TURBOCHARGER LTD
- Filing Date
- 2025-11-14
- Publication Date
- 2026-07-30
Smart Images
Figure JP2025039929_30072026_PF_FP_ABST
Abstract
Description
Control device, gas engine, control method and program
[0001] This disclosure relates to a control device, a gas engine, a control method, and a program. This disclosure claims priority under Japanese Patent Application No. 2025-009956, filed in Japan on January 23, 2025, the contents of which are incorporated herein by reference.
[0002] Figure 1 shows an example of the schematic equipment configuration of a gas engine 100. The gas engine 100 includes a fuel supply system L0, an air supply system L3, and an engine body E, the engine body E comprising a plurality of cylinders Cly1, Cly2, ... The air supply system L3 branches out to the same number of cylinders Cly1, Cly2, and the branched tributaries (intake pipes) are connected to cylinders Cly1, Cly2, etc. The fuel supply system L0 branches into intake pipes L1, L2, ... Intake pipe L1 is connected to intake pipe L31 which is connected to cylinder Cly1, and intake pipe L2 is connected to intake pipe L32 which is connected to cylinder Cly2. A mixture of gas fuel supplied through the fuel supply system L0 and air supplied through the air supply system L3 is supplied to each of the cylinders Cly1, Cly2, ... through intake pipes L31, L32, etc. An electronic valve V0 is provided in the fuel supply system L0, a fuel injector I1 is provided in the intake manifold L1, and a fuel injector I2 is provided in the intake manifold L2. Downstream of the electronic valve V0 in the fuel supply system L0, a pressure sensor C0 is provided to measure the gas fuel pressure upstream of the fuel injectors I1 and I2, and upstream of the electronic valve V0, a pressure sensor C2 is provided to measure the gas fuel pressure upstream of the electronic valve V0. In the air supply system L3, a pressure sensor C1 is provided to measure the intake pressure (pressure of the mixture of gas fuel and air, which in some cases is almost 100% air pressure) downstream of the fuel injectors I1 and I2.
[0003] In the gas engine 100, the fuel flow rate supplied to the cylinder Cly1, etc., is controlled by the fuel injector I1, etc., and the fuel differential pressure (fuel pressure upstream of the fuel injector I1, etc. minus intake pressure downstream) is controlled by the electronic valve V0. If the fuel differential pressure deviates from the appropriate value, the fuel injector I1, etc., may experience malfunctions such as insufficient injection amount or injection failure.
[0004] More specifically, when controlling fuel differential pressure with an electronic valve V0, the fuel differential pressure is generally controlled using a control logic as illustrated in Figure 6. That is, the target fuel differential pressure and the current fuel differential pressure are input to a feedback controller 61, the feedback controller 61 calculates an opening degree that brings the deviation between them closer to zero, and controls the electronic valve V0 with the calculated opening degree. At this time, changes in the fuel flow rate of the fuel injector I1, etc., downstream of the electronic valve V0 act as a disturbance to the fuel differential pressure control of the electronic valve V0. Specifically, when a change in the fuel injection amount occurs in the downstream fuel injector I1, etc., the balance between the fuel flow rate passing through the electronic valve V0 and the fuel flow rate passing through the fuel injector I1, etc. is temporarily disrupted, causing a change in fuel differential pressure. In particular, during transient operations such as load application and load removal, a large change in fuel flow rate occurs in the fuel injector I1 in a short period of time. In the conventional control shown in Figure 6, control starts after a change in fuel differential pressure occurs after a change in fuel flow rate, resulting in a response delay. As a result, a significant drop in fuel differential pressure occurs when load is applied, causing an unintended decrease in fuel flow rate in the fuel injector I1, etc., and worsening the load response. When the load is removed, an overshoot of fuel differential pressure occurs, resulting in injection failure in the fuel injector I1, etc.
[0005] Patent Document 1 discloses a method for controlling the opening of an EGR valve in an engine that includes an EGR device that recirculates a portion of the exhaust gas after combustion to the intake side. This method involves detecting the actual engine speed and fuel injection amount, calculating the output-corrected EGR opening amount corresponding to the actual engine speed and fuel injection amount using a map that shows the relationship between the actual engine speed, fuel injection amount, and output-corrected EGR opening amount, and controlling the opening of the EGR valve. Patent Document 1 does not disclose a method for controlling the differential pressure between the upstream and downstream sides of a fuel injection device to a target fuel differential pressure when the fuel flow rate supplied to the engine changes.
[0006] Japanese Patent Publication No. 2012-163107
[0007] Even when fuel flow rates change, there is a need for control that can bring the fuel pressure difference between the upstream and downstream sides of the fuel injection system closer to the target pressure difference.
[0008] This disclosure provides a control device, a gas engine, a control method, and a program that can solve the above-mentioned problems.
[0009] According to one aspect of the present disclosure, the control device is an engine including a fuel supply system for supplying fuel, a valve provided in the fuel supply system, a fuel injection device for adjusting the flow rate of the fuel downstream of the valve, and an air supply system for supplying air connected to the fuel supply system downstream of the fuel injection device, and controls the pressure difference between the fuel pressure upstream of the fuel injection device and the intake pressure of the engine downstream of the fuel injection device to a predetermined target differential pressure by adjusting the opening degree of the valve, and comprises means for controlling the valve with an opening degree obtained by summing a first opening degree of the valve corresponding to the flow rate of fuel injected by the fuel injection device and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.
[0010] According to one aspect of the present disclosure, a gas engine includes a fuel supply system for supplying gaseous fuel, a valve provided in the fuel supply system, a fuel injection device downstream of the valve for adjusting the flow rate of the gaseous fuel, an air supply system downstream of the fuel injection device for supplying air connected to the fuel supply system, and a control device that controls the pressure difference between the gaseous fuel pressure upstream of the fuel injection device and the intake pressure of the gas engine downstream of the fuel injection device to a predetermined target differential pressure by adjusting the opening degree of the valve, wherein the control device controls the valve with an opening degree obtained by summing a first opening degree of the valve corresponding to the flow rate of the gaseous fuel injected by the fuel injection device and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.
[0011] According to one aspect of the present disclosure, a control method is provided for an engine including a fuel supply system for supplying fuel, a valve provided in the fuel supply system, a fuel injection device for adjusting the flow rate of the fuel downstream of the valve, and an air supply system for supplying air connected to the fuel supply system downstream of the fuel injection device, wherein the control method controls the valve to a predetermined target differential pressure by adjusting the opening degree of the valve, wherein the control device controls the valve to an opening degree obtained by summing a first opening degree of the valve corresponding to the flow rate of fuel injected by the fuel injection device and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.
[0012] According to one aspect of the present disclosure, a program causes a computer to execute a process for controlling the pressure difference between the fuel pressure upstream of the fuel injector and the intake pressure of the engine downstream of the fuel injector to a predetermined target differential pressure by adjusting the opening degree of the valve in an engine including a fuel supply system for supplying fuel, a valve provided in the fuel supply system, a fuel injector downstream of the valve for adjusting the flow rate of the fuel downstream of the valve, and an air supply system connected to the fuel supply system downstream of the fuel injector. The program controls the valve with an opening degree obtained by summing a first opening degree of the valve corresponding to the flow rate of fuel injected by the fuel injector and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.
[0013] According to the control device, gas engine, control method, and program described above, even when the fuel flow rate changes, the fuel differential pressure between the upstream and downstream sides of the fuel injection device can be brought closer to the target differential pressure.
[0014] These are schematic diagrams of the gas engine according to each embodiment. This is a diagram showing an example of the control logic of an electronic valve according to the first embodiment. This is a diagram showing an example of the control logic of an electronic valve according to the second embodiment. This is a diagram showing an example of the control logic of an electronic valve according to the third embodiment. This is a diagram illustrating a function according to the third embodiment. This is a diagram showing an example of the control logic of a conventional electronic valve. These are schematic diagrams showing an example of the hardware configuration of the control device according to each embodiment.
[0015] <First Embodiment> (Configuration) The control method of the electronic valve V0 according to this embodiment will be described below with reference to Figures 1 to 3. Figure 1 is a schematic configuration diagram of the gas engine according to each embodiment. The schematic configuration of the gas engine 100 is as described above. In other words, the fuel supply system L0 is provided with an electronic valve V0 that adjusts the pressure of the gas fuel, and fuel injection devices I1, I2, etc. that adjust the flow rate of the gas fuel. Gas fuel is supplied through the fuel supply system L0, air is supplied through the air supply system L3, and a mixture of gas fuel and air is supplied to the engine body E. The opening degree of the electronic valve V0 for adjusting the fuel differential pressure is controlled by the control device 10. The control device 10 acquires the pressure measured by the pressure sensors C0 and C1 and the output of the gas engine 100 or a value related to the output, and calculates the opening degree of the electronic valve V0 based on the fuel differential pressure and the output of the gas engine 100. An example of the specific control logic of the electronic valve V0 according to the first embodiment is shown in Figure 2.
[0016] Figure 2 shows an example of the control logic for an electronic valve according to the first embodiment. The control device 10 includes a lookup table 11, an FB controller 12, and an adder 13. The control device 10 stores a target differential pressure, which is a target value for the differential pressure between the upstream and downstream sides of a fuel injection device I1, etc.
[0017] The lookup table 11 stores the output (current output) of the gas engine 100 in association with the opening degree of the electronic valve V0. For example, it is set so that the opening degree is 5% for an output of 0%, and the opening degree is 20% for an output of 20%. In the lookup table 11, for output values that indicate an operating state where the output is constant (e.g., rated), the opening degree corresponding to the output is set, and for output values that indicate transient operation such as load application or load removal, the opening degree is set according to the output while also taking into account disturbances caused by changes in fuel flow rate in the fuel injector I1, etc. In other words, the lookup table 11 has values pre-set to compensate for the response delay due to feedback control and enable proactive opening degree control according to the output of the gas engine 100.
[0018] The FB controller 12 acquires the target differential pressure of the gaseous fuel and the current differential pressure, which is the current value of the differential pressure between the upstream and downstream sides of the fuel injection device I1, etc., based on the pressures measured by pressure sensors C0 and C1. It then calculates the opening degree of the electronic valve V0 to bring the current differential pressure closer to the target differential pressure using feedback control such as PI control or PID control.
[0019] The adder 13 adds the opening degree of the electronic valve V0, which corresponds to the current output of the gas engine 100 calculated based on the lookup table 11, with the opening degree of the electronic valve V0 output by the FB controller 12. The control device 10 controls the electronic valve V0 with the opening degree after the adder 13 has added the values.
[0020] (Operation) The process flow for calculating the opening degree of the electronic valve V0 based on the control logic in Figure 2 will be explained below. The control device 10 acquires fuel flow command values to the fuel injectors I1, I2, etc., and measured values of the gas fuel flow rate injected by the fuel injectors I1, I2, etc., and inputs these command values or measured values into a function that converts the fuel flow command value or measured value of fuel flow rate into the output of the gas engine 100 to calculate the output of the gas engine 100. Alternatively, the control device 10 may acquire measured values of the output of the gas engine 100 or command values of the output. The control device 10 refers to the lookup table 11 to acquire the opening degree of the electronic valve V0 according to the output of the gas engine 100.
[0021] In parallel with this, the control device 10 acquires the pressure measured by pressure sensors C0 and C1 and calculates the current differential pressure. For example, the control device 10 subtracts the pressure measured by pressure sensor C1 from the pressure measured by pressure sensor C0 to obtain the differential pressure, and sets this value as the current differential pressure. Next, the control device 10 inputs the calculated current differential pressure and target differential pressure to the FB controller 12. The FB controller 12 calculates and outputs the opening degree of the electronic valve V0 that can achieve the target differential pressure. Next, the control device 10 uses an adder 13 to add the opening degree of the electronic valve V0 calculated by the FB controller 12 to the opening degree of the electronic valve V0 corresponding to the current output of the gas engine 100 obtained from the lookup table 11, and controls the electronic valve V0 with the added opening degree.
[0022] For example, when the load is increased from 0% to 20% during load application, the control device 10 refers to the lookup table 11 to obtain an opening of 5% when the output of the gas engine 100 is 0%, and controls the electronic valve V0 by adding the value output by the FB controller 12. When the output increases to 20%, it refers to the lookup table 11 to obtain an opening of 20%, adjusts by adding the value output by the FB controller 12, and controls the electronic valve V0. The gain of the FB controller 12 is set conservatively, and the electronic valve V0 is mainly controlled by the opening corresponding to the output registered in the lookup table 11. This improves responsiveness compared to the conventional logic exemplified in Figure 6.
[0023] (Effects) As described above, according to this embodiment, the opening degree of the electronic valve V0 is controlled by adding the opening degree of the electronic valve V0 corresponding to the current engine output obtained by referring to the lookup table 11 to the opening degree of the electronic valve V0 based on feedback control using the target differential pressure and the current differential pressure as inputs, and using that opening degree as a command value. At this time, the valve opening degree output from the lookup table 11 acts as a correction term that takes into account disturbances caused by changes in the fuel flow rate injected by the fuel injector I1, etc. For example, during transient operation such as load application or load removal, the output of the gas engine 100 changes, so the opening degree referenced from the lookup table 11 increases or decreases faster than the opening degree output by the FB controller 12. By setting an appropriate opening degree according to the output in the lookup table 11, changes in the fuel flow rate in the fuel injector I1, etc. during transient operation are indirectly taken into account. The opening degree according to the output is calculated in advance based on the lookup table 11, this opening degree is adjusted by feedback control, and the electronic valve V0 is controlled using the opening degree command value. As a result, compared to conventional control, the electronic valve V0 can be controlled quickly with an appropriate opening degree according to the gas fuel flow rate, even in situations where the fuel flow rate changes significantly, improving responsiveness. For example, it can suppress a large drop in fuel differential pressure when a load is applied, or an overshoot of fuel differential pressure when a load is removed.
[0024] <Second Embodiment> (Configuration) The opening degree control of the electronic valve V0 according to the second embodiment will be described below with reference to Figure 3. Figure 3 is a diagram showing an example of the control logic of the electronic valve according to the second embodiment. In the control logic according to the second embodiment, a lookup table 11a is used instead of the lookup table 11 of the first embodiment. The other configurations are the same as in the first embodiment.
[0025] The lookup table 11a stores the fuel flow command value for the fuel injector I1, etc., and the opening degree of the electronic valve V0 in association with it. For fuel flow command values indicating an operating state where the output is constant, the lookup table 11a sets an opening degree corresponding to the fuel flow command value, and for fuel flow command values indicating transient operation such as load application or load removal, it sets an opening degree that takes into account disturbances caused by changes in fuel flow in the fuel injector I1, etc. By setting an appropriate opening degree according to the fuel flow command value in the lookup table 11a, it is possible to take into account changes in fuel flow in the fuel injector I1, etc. during transient operation. The same fuel flow command value is commanded to the fuel injectors I1, I2, etc.
[0026] (Operation) The process flow for calculating the opening degree of the electronic valve V0 based on the control logic in Figure 3 will be explained below. The control device 10 obtains a fuel flow command value to the fuel injection device I1, etc. The control device 10 obtains the opening degree of the electronic valve V0 corresponding to the fuel flow command value by referring to the lookup table 11a. In parallel with this, the control device 10 obtains the pressure measured by the pressure sensors C0 and C1 and calculates the current differential pressure in the same manner as in the first embodiment. The control device 10 inputs the calculated current differential pressure and target differential pressure to the FB controller 12 and obtains the opening degree of the electronic valve V0 calculated by feedback control. Next, the control device 10 uses the adder 13 to add the opening degree of the electronic valve V0 calculated by the FB controller 12 to the opening degree of the electronic valve V0 corresponding to the current fuel flow command value obtained from the lookup table 11a, and controls the electronic valve V0 with the added opening degree.
[0027] (Effects) As described above, according to this embodiment, the opening degree of the electronic valve V0 based on feedback control using the target differential pressure and the current differential pressure as inputs is combined with the opening degree of the electronic valve V0 corresponding to the current fuel flow command value obtained by referring to the lookup table 11a, and the electronic valve V0 is controlled using this opening degree as the command value. At this time, the valve opening degree output from the lookup table 11a acts as a correction term that takes into account disturbances caused by changes in fuel flow in the fuel injectors I1, I2, etc. For example, during transient operation such as load application or load cutoff, the output of the gas engine 100, i.e., the fuel flow command value, changes, so the opening degree obtained from the lookup table 11a increases or decreases faster than the opening degree output by the FB controller 12. The opening degree corresponding to the fuel flow command value is calculated in advance based on the lookup table 11a, and the value adjusted by feedback control is used as the opening degree command value to control the electronic valve V0. As a result, compared to conventional control, the electronic valve V0 can be controlled more quickly with an opening degree corresponding to the gas fuel flow rate, and a significant drop in fuel differential pressure and overshoot can be suppressed. Compared to the first embodiment, by using a fuel flow command value that more directly reflects the flow rate of the fuel injector I1, etc., as input to the lookup table 11a, more accurate opening degree control can be expected than in the first embodiment.
[0028] <Third Embodiment> (Configuration) The opening degree control of the electronic valve V0 according to the third embodiment will be described below with reference to Figures 4 and 5. Figure 4 is a diagram showing an example of the control logic of the electronic valve according to the third embodiment. In the control logic according to the third embodiment, a function (or lookup table) 14 is used instead of the lookup table 11 of the first embodiment. The other configurations are the same as in the first embodiment.
[0029] As shown in Figure 4, function 14 is the fuel flow command value Q. Ｇ Fuel temperature t, pressure P upstream of electronic valve V0. １ , Target value P of pressure downstream of electronic valve V0 ２ This function takes the input Q as input and outputs the opening degree of the electronic valve V0 that is suitable for these conditions. Here, the fuel flow command value Q is Q. Ｇ (m ３ / h) is the value commanded by the control device 10 to the fuel injection device I1 and the like. The fuel temperature t (°C) is the temperature of the gaseous fuel measured by a temperature sensor (not shown) provided in the fuel supply system L0. The valve upstream pressure P １ (MPa) is the pressure measured by the pressure sensor C2. The valve downstream pressure target value P ２ is the value obtained by adding the target differential pressure to the pressure measured by the pressure sensor C1. The function 14 is such that when P ２ > P １ ÷2 holds, the required Cv value, which is the Cv value required for the electronic valve V0 according to the following formula (1) described in Table 51 of FIG. 5, is calculated.
[0030]
[0031] P ２ ≦P １ ÷2 holds, the function 14 calculates the required Cv value according to the following formula (2) described in Table 51 of FIG. 5.
[0032]
[0033] G Ｇ is the specific gravity of the gas (gaseous fuel) when the specific gravity of air is taken as 1. The required Cv value is the differential pressure between the upstream side and the downstream side of the fuel injection device I1 and the like is controlled to the target differential pressure under the conditions of the fuel flow rate command value Q Ｇ , the fuel temperature t, and the valve upstream pressure P １ , and the flow rate of the fuel injected by the fuel injection device I1 and the like becomes the fuel flow rate indicated by the fuel flow rate command value Q Ｇ . It is the Cv value of the electronic valve V0 required to achieve this. The function 14 has a conversion map 52 in FIG. 5, and converts the required Cv value calculated by the above formula (1) or formula (2) into an opening degree (FF control opening degree in the figure) for achieving the required Cv value. The conversion map 52 is a Cv value curve specific to the electronic valve V0. The vertical axis of the conversion map 52 is the opening degree of the electronic valve V0, and the horizontal axis is the Cv value of the electronic valve V0. The FF (feedforward) control opening degree is the fuel flow rate command value Q Ｇ input to the function 14, the fuel temperature t, and the valve upstream pressure P １ under the conditions, and the fuel flow rate command value Q ＧThis is a value calculated in advance for the opening degree of the electronic valve V0 required to achieve the fuel flow rate and target differential pressure indicated. An offset may be added to the opening degree output by function 14.
[0034] Function 14 may be configured as a lookup table. That is, the lookup table is the fuel flow command value Q Ｇ Fuel temperature t, valve upstream pressure P １ and the target value P of the valve downstream pressure ２ The opening degree of the electronic valve V0 is set in correspondence with the control device 10, and Q Ｇ , t, P １ and P ２ Alternatively, the opening degree of the electronic valve V0 corresponding to the FF control opening degree may be calculated in advance by referring to a lookup table using the above method.
[0035] (Operation) The following describes the process flow for calculating the opening degree of the electronic valve V0 based on the control logic in Figure 4. The control device 10 commands the fuel flow rate Q to the fuel injector I1, etc. Ｇ Fuel temperature t, valve upstream pressure P １ The control device 10 obtains the target value P of the valve downstream pressure. ２ Calculate Q Ｇ , t, P １ , P ２ The input is given to function 14 to obtain the opening degree of the electronic valve V0 (the FF control opening degree mentioned above). In parallel with this, the control device 10 calculates the current differential pressure based on the pressures measured by pressure sensors C0 and C1. The control device 10 inputs the calculated current differential pressure and target differential pressure to the FB controller 12 and obtains the opening degree of the electronic valve V0 calculated by feedback control. Next, the control device 10 uses the adder 13 to add the opening degree of the electronic valve V0 calculated by the FB controller 12 to the opening degree of the electronic valve V0 output by function 14, and controls the electronic valve V0 with the added opening degree.
[0036] (Effects) As described above, according to this embodiment, the required Cv value is calculated from the fuel flow command value, fuel temperature, valve upstream pressure, and downstream pressure target value. The opening of the electronic valve V0 is controlled by adding the opening based on feedback control to the valve opening (FF control opening) calculated from this required Cv value and the Cv value opening characteristics of the electronic valve V0. At this time, the FF control opening acts as a correction term that takes into account disturbances caused by changes in fuel flow rate in the fuel injection device I1, etc. By adding a correction based on physical laws and valve-specific flow characteristics (or a lookup table created based on that function), more accurate and robust opening control can be expected compared to the first and second embodiments.
[0037] Figure 7 is a schematic block diagram showing the hardware configuration of a control device according to an embodiment. The computer 90 includes a processor 91, main memory 92, storage 93, and interface 94. The control device 10 described above is implemented in the computer 90. The operation of each of the above-described processing units is stored in the storage 93 in the form of a program. The processor 91 reads the program from the storage 93, loads it into the main memory 92, and executes the above-described processing according to the program. The processor 91 allocates storage areas in the main memory 92 corresponding to each of the above-described storage units according to the program. Examples of the processor 91 include a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and a microprocessor.
[0038] The program may be for implementing some of the functions that the computer 90 is to perform. For example, the program may perform functions in combination with other programs already stored in storage, or in combination with other programs implemented in other devices. In other embodiments, the computer 90 may include, in addition to or instead of the above configuration, a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device). Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions implemented by the processor 91 may be implemented by the integrated circuit. Such an integrated circuit is also included as an example of a processor.
[0039] Examples of storage 93 include HDDs (Hard Disk Drives), SSDs (Solid State Drives), magnetic disks, magneto-optical disks, CD-ROMs (Compact Disc Read Only Memory), DVD-ROMs (Digital Versatile Disc Read Only Memory), and semiconductor memory. Storage 93 may be an internal medium directly connected to the bus of the computer 90, or an external medium connected to the computer 90 via an interface 94 or a communication line. When this program is delivered to the computer 90 via a communication line, the computer 90 that receives the delivery may expand the program into the main memory 92 and execute the above processing. In at least one embodiment, storage 93 is a tangible storage medium that is not temporary. The program may be for realizing some of the functions described above. Furthermore, the program may be a so-called differential file (differential program) that realizes the functions described above in combination with other programs already stored in storage 93.
[0040] As described above, several embodiments relating to this disclosure have been explained, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be carried out in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.
[0041] <Note> The control device, gas engine, control method, and program described in each embodiment can be understood, for example, as follows.
[0042] (1) A control device according to the first embodiment is an engine including a fuel supply system for supplying fuel, a valve provided in the fuel supply system, a fuel injection device for adjusting the flow rate of the fuel downstream of the valve, and an air supply system for supplying air connected to the fuel supply system downstream of the fuel injection device, wherein the control device controls the pressure difference between the fuel pressure upstream of the fuel injection device and the intake pressure of the engine downstream of the fuel injection device to a predetermined target differential pressure by adjusting the opening degree of the valve, and comprises means for controlling the valve with an opening degree obtained by summing a first opening degree of the valve corresponding to the fuel flow rate injected by the fuel injection device and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.
[0043] (2) The control device according to the second embodiment is the control device of (1), wherein the controlling means calculates the first opening degree based on a lookup table that stores the engine output and the valve opening degree corresponding to the engine output in association with each other, and the engine output. Even when the fuel flow rate changes, the fuel differential pressure between the upstream and downstream sides of the fuel injection device can be brought closer to the target differential pressure.
[0044] (3) The control device according to the third embodiment is the control device of (1), wherein the controlling means calculates the first opening degree based on a lookup table that stores in association between a command value for the fuel flow rate supplied to the engine and the opening degree of the valve corresponding to the command value for the fuel flow rate, and the command value for the fuel flow rate. Even when the fuel flow rate changes, the fuel differential pressure between the upstream and downstream sides of the fuel injection device can be brought closer to the target differential pressure.
[0045] (4) The control device according to the fourth embodiment is the control device according to (1), wherein the controlling means takes as input a command value for the fuel flow rate supplied to the engine, the temperature of the fuel, the pressure of the fuel upstream of the valve, and a target value for the pressure of the fuel downstream of the valve and upstream of the fuel injector, and calculates the first opening degree based on the command value for the fuel flow rate, the temperature of the fuel, the pressure of the fuel upstream of the valve, the pressure of the fuel injector to the target differential pressure, while controlling the pressure difference to the target differential pressure under the conditions of the command value for the fuel flow rate, the temperature of the fuel, and the pressure of the fuel upstream of the valve, and the first opening degree based on the command value for the fuel flow rate, the temperature of the fuel, the pressure of the fuel upstream of the valve, and the target value for the pressure of the fuel downstream of the valve and upstream of the fuel injector.
[0046] (5) A gas engine according to a fifth embodiment comprises a fuel supply system for supplying gas fuel, a valve provided in the fuel supply system, a fuel injection device downstream of the valve for adjusting the flow rate of the gas fuel, an air supply system downstream of the fuel injection device for supplying air connected to the fuel supply system, and a control device that controls the pressure difference between the gas fuel pressure upstream of the fuel injection device and the intake pressure of the gas engine downstream of the fuel injection device to a predetermined target differential pressure by adjusting the opening degree of the valve, wherein the control device controls the valve with an opening degree that is the sum of a first opening degree of the valve corresponding to the flow rate of the gas fuel injected by the fuel injection device and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.
[0047] (6) A control method according to a sixth aspect is a control method for an engine including a fuel supply system for supplying fuel, a valve provided in the fuel supply system, a fuel injection device for adjusting the flow rate of the fuel downstream of the valve, and an air supply system for supplying air connected to the fuel supply system downstream of the fuel injection device, wherein the control method controls the valve to a predetermined target differential pressure by adjusting the opening degree of the valve, wherein the control device controls the valve to an opening degree obtained by summing a first opening degree of the valve corresponding to the flow rate of fuel injected by the fuel injection device and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.
[0048] (7) A program according to the seventh aspect is a program that causes a computer to execute a process for controlling the pressure difference between the fuel pressure upstream of the fuel injection device and the intake pressure of the engine downstream of the fuel injection device to a predetermined target differential pressure by adjusting the opening degree of the valve, in an engine including a fuel supply system for supplying fuel, a valve provided in the fuel supply system, a fuel injection device for adjusting the flow rate of the fuel downstream of the valve, and an air supply system for supplying air connected to the fuel supply system downstream of the fuel injection device, wherein the program controls the valve with an opening degree obtained by summing a first opening degree of the valve corresponding to the flow rate of fuel injected by the fuel injection device and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.
[0049] According to the control device, gas engine, control method, and program described above, even when the fuel flow rate changes, the fuel differential pressure between the upstream and downstream sides of the fuel injection device can be brought closer to the target differential pressure.
[0050] Cly1, Cly2... Cylinders C0, C1, C2... Pressure sensors E... Engine body I1, I2... Fuel injectors L0... Fuel supply system L1, L2, L31, L32... Intake pipes L3... Air supply system V0... Electronic valves 10... Control unit 11, 11a... Look-up tables 12... FB controller 13... Adder 14... Function 90... Computer 91... Processor 92... Main memory 93... Storage 94... Interface 100... Gas engine
Claims
1. An engine comprising a fuel supply system for supplying fuel, a valve provided in the fuel supply system, a fuel injection device downstream of the valve for adjusting the flow rate of the fuel, and an air supply system downstream of the fuel injection device for supplying air connected to the fuel supply system, wherein the control device controls the pressure difference between the fuel pressure upstream of the fuel injection device and the intake pressure of the engine downstream of the fuel injection device to a predetermined target differential pressure by adjusting the opening degree of the valve, the control device comprising means for controlling the valve with an opening degree obtained by summing a first opening degree of the valve corresponding to the flow rate of fuel injected by the fuel injection device and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.
2. The control device according to claim 1, wherein the control means calculates the first opening degree based on the engine output and the valve opening degree corresponding to the engine output, and the engine output.
3. The control device according to claim 1, wherein the control means calculates the first opening degree based on a lookup table that stores a command value for the fuel flow rate supplied to the engine and the opening degree of the valve corresponding to the command value for the fuel flow rate, and the command value for the fuel flow rate.
4. The control device according to claim 1, wherein the control means takes as input a command value for the fuel flow rate supplied to the engine, the temperature of the fuel, the pressure of the fuel upstream of the valve, and a target value for the pressure of the fuel downstream of the valve and upstream of the fuel injector, and outputs a function that outputs an opening degree corresponding to the Cv value of the valve necessary to make the flow rate of the fuel injected by the fuel injector the flow rate indicated by the command value of the fuel flow rate, while controlling the pressure difference to the target differential pressure under the conditions of the command value of the fuel flow rate, the temperature of the fuel, and the pressure of the fuel upstream of the valve, and calculates the first opening degree based on the command value of the fuel flow rate, the temperature of the fuel, the pressure of the fuel upstream of the valve, and the target value for the pressure of the fuel downstream of the valve and upstream of the fuel injector.
5. A gas engine comprising: a fuel supply system for supplying gaseous fuel; a valve provided in the fuel supply system; a fuel injection device downstream of the valve for adjusting the flow rate of the gaseous fuel; an air supply system downstream of the fuel injection device for supplying air connected to the fuel supply system; and a control device that controls the pressure difference between the gaseous fuel pressure upstream of the fuel injection device and the intake pressure of the gas engine downstream of the fuel injection device to a predetermined target differential pressure by adjusting the opening degree of the valve, wherein the control device controls the valve with an opening degree obtained by summing a first opening degree of the valve corresponding to the flow rate of the gaseous fuel injected by the fuel injection device and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.
6. A control method for an engine comprising a fuel supply system for supplying fuel, a valve provided in the fuel supply system, a fuel injection device for adjusting the flow rate of the fuel downstream of the valve, and an air supply system for supplying air connected to the fuel supply system downstream of the fuel injection device, wherein the control device controls the valve with an opening degree obtained by summing a first opening degree of the valve corresponding to the flow rate of fuel injected by the fuel injection device, and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.
7. A program that causes a computer to execute a process for controlling the pressure difference between the fuel pressure upstream of the fuel injector and the intake pressure of the engine downstream of the fuel injector to a predetermined target differential pressure by adjusting the opening degree of the valve, in an engine including a fuel supply system for supplying fuel, a valve provided in the fuel supply system, a fuel injector downstream of the valve for adjusting the flow rate of the fuel, and an air supply system connected to the fuel supply system downstream of the fuel injector for supplying air, wherein the process controls the valve with an opening degree obtained by summing a first opening degree of the valve corresponding to the flow rate of fuel injected by the fuel injector and a second opening degree of the valve calculated by feedback control based on the deviation between the measured value of the pressure difference and the target differential pressure.