JP2007032528A - Operation control system for internal combustion type prime mover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an operation control system for operating an internal combustion type prime mover by using recycled gas which contains a certain amount of component which gives adverse effects to the internal combustion type prime mover. <P>SOLUTION: The operation control system for a dual fuel engine 1 comprises a biomass gas supply source 11, a LP gas supply source 14, and a controller 21. The controller 21 controls the supply of fuel from the biomass gas supply source 11 and the LP gas supply source 14 to the dual fuel engine 1. LP gas is only supplied during the time from starting to finishing warm-up operation, and it is changed over into woody biomass gas after finishing warm-up operation. During a predetermined time before stopping, the woody biomass gas is changed over into the LP gas. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an operation control system for an internal combustion prime mover that uses, as a fuel, a recycle gas containing components that adversely affect an internal combustion engine such as wood tar.

In recent years, from the viewpoint of CO ₂ reduction in consideration of environmental problems, it is produced from biomass gas generated from biomass such as forestry waste biomass including woody biomass, agricultural waste biomass, and food waste biomass, and waste tires, etc. There is an increasing demand for using recycled gas containing the generated gas as a fuel for an internal combustion motor for driving a generator or the like.

  However, this type of recycle gas contains components that adversely affect the internal combustion motor. For example, in the case of woody biomass gas, the woody biomass gas produced by the gasifier contains 1000 ppm or more of wood tar, and the adverse effect of this wood tar on the gas engine is a major problem.

  The standard of the content of wood tar that can use biomass gas as fuel for ordinary gas engines is about 10 ppm or less. However, in order to achieve a content of 10 ppm or less, a special filter device for tar removal is provided on the gasifier side, or high performance with high tar removal efficiency as described in Patent Document 1, for example. It is necessary to install additional tar reforming equipment. When the filter device is provided, not only the equipment cost increases, but also the complicated filter replacement work needs to be periodically executed, so that the work load and cost required for maintenance are also greatly increased. Similarly, additional installation of a high-performance tar reformer will lead to increased construction costs and maintenance work for the entire facility.

  On the other hand, it is relatively easy to suppress the tar content in the biomass gas to about 100 ppm. However, when this biomass gas containing about 100 ppm of tar is used as a fuel for ordinary gas engines, the disassembly inspection interval is extremely shortened compared to the case of using a general-purpose fuel that does not contain impurities such as LP gas. If the inside of the gas engine is not cleaned frequently, engine troubles cannot be avoided, leading to a decrease in reliability. Specifically, if the engine is not cleaned frequently, tar adhering to the intake valve, exhaust valve, spark plug, etc. at the start or stop of operation will stick when the gas engine is cooled after the stop. The stuck tar causes various troubles such as the gas engine does not start at the next start-up and the intake and exhaust valves do not operate smoothly.

JP 2001-172648 A

  The present invention has an adverse effect on an internal combustion engine without using a special filter or a high-performance gas reformer, and while suppressing the frequency of overhaul of the internal combustion engine to the same level as when using a general-purpose fuel. It is an object of the present invention to make it possible to operate an internal combustion prime mover with a recycle gas containing a certain amount of components (about 100 ppm in the case of tar).

  The present invention includes an internal combustion prime mover that can be operated using both a recycle gas containing impurities and a general-purpose fuel as a fuel, a recycle gas supply source capable of supplying the recycle gas to the internal combustion prime mover, and the general-purpose fuel as the internal combustion engine. In the operation control system for an internal combustion engine that includes a general-purpose fuel supply source that can be supplied to the engine, only the general-purpose fuel is supplied to the internal combustion engine from the start of the internal combustion engine to the end of the warm-up operation. After the operation of the engine, the fuel supplied to the internal combustion engine is switched from the general-purpose fuel to the recycle gas, and the fuel supplied to the internal combustion engine for a predetermined time before the stop of the internal combustion engine is The recycle gas supply source and the general-purpose fuel supply source are used to switch the recycle gas to the general-purpose fuel. Characterized in that it comprises a control means for controlling the fuel supply to the machine, provides an operation control system for an internal combustion engine.

  When the internal combustion prime mover is started, the temperature of the internal combustion prime mover has not risen sufficiently and is relatively low. If recycle gas is supplied as fuel to the internal combustion prime mover in this relatively low temperature state, impurities such as tar contained in the recycle gas are in a low viscosity state, so the intake valve, exhaust valve, spark plug, etc. of the internal combustion prime mover Easy to adhere to. Impurities such as tar adhering to the intake valve, exhaust valve, spark plug, etc. are fixed after the internal combustion engine is stopped, the gas engine does not start at the next startup, the intake valve or exhaust valve does not operate smoothly, etc. It causes various troubles. However, in the operation control system for an internal combustion engine according to the present invention, impurities such as tar are included from the start of the internal combustion engine to the end of the warm-up operation, that is, until the temperature rises sufficiently after the startup of the internal combustion engine. Since general-purpose fuel, not recycle gas, is supplied to the internal combustion prime mover, impurities such as tar do not adhere to the internal combustion prime mover during startup.

  If the recycle gas remains in the internal combustion prime mover (cylinder chamber or the like) when the internal combustion prime mover is stopped, the temperature of the recycle gas remaining also decreases as the temperature of the internal combustion prime mover after the operation stops. As a result, the viscosity of impurities such as tar contained in the recycle gas decreases, and adheres to and adheres to the intake valve, exhaust valve, spark plug, etc. of the internal combustion motor, causing various troubles. However, in the operation control system for the internal combustion engine according to the present invention, the fuel supplied to the internal combustion engine is switched from the recycled gas to the general-purpose fuel for a predetermined time before the internal combustion engine is stopped. Sometimes no recycle gas remains inside the internal combustion prime mover. Further, tar and the like adhering during the operation using the recycle gas as a fuel is cleaned by the operation using the general-purpose fuel. Therefore, impurities such as tar do not adhere to the internal combustion prime mover when stopped.

  As described above, according to the operation control system for an internal combustion engine according to the present invention, since impurities such as tar do not adhere to the internal combustion engine during start-up and stop, a special filter or a high-performance gas reformer is used. The amount of impurities that adversely affect the internal combustion engine is reduced to a certain level (100 ppm in the case of tar) without using a quality device and while suppressing the frequency of overhaul of the internal combustion engine to the same level as when using general-purpose fuel. About) Recyclable gas contained can be used to operate the internal combustion motor.

  Specifically, the apparatus further comprises temperature detection means for detecting the temperature of the cooling water of the internal combustion prime mover, and the supply control means is configured such that the coolant temperature detected by the temperature detection means after the start of the internal combustion prime mover is previously detected. When a predetermined set temperature is reached, it is determined that the warm-up operation has ended, and the fuel supplied to the internal combustion engine is switched from the general-purpose fuel to the recycle gas.

  Alternatively, the fuel supply control means determines that the warm-up operation has ended when a time that can be considered that the temperature of the internal combustion prime mover has sufficiently increased after the start of the internal combustion prime mover has elapsed, and supplies the fuel to be supplied to the internal combustion prime mover to the The general-purpose fuel may be switched to the recycle gas.

  According to the operation control system for an internal combustion engine according to the present invention, recycling including impurities such as tar is performed during a predetermined period from the start of the internal combustion engine to the end of the warm-up operation and the stop of the internal combustion engine. Since general-purpose fuel, not gas, is supplied to the internal combustion prime mover, the frequency of overhaul of the internal combustion prime mover is almost the same as when ordinary general-purpose fuel is used without using special filters or high-performance gas reformers. While being suppressed, the internal combustion prime mover can be operated with a recycle gas containing a certain amount of components (about 100 ppm in the case of tar) that adversely affect the internal combustion prime mover.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  The operation control system for an internal combustion engine according to the embodiment of the present invention shown in FIG. 1 is a dual fuel engine that is an internal combustion engine that can be operated using both woody biomass (recycled gas) and LP gas (general purpose gas) as fuel. 1 is provided. The dual fuel engine 1 drives a generator 2. The dual fuel engine 1 includes a cooling water pipe 3 through which cooling water circulates in addition to an intake valve, an exhaust valve, a spark plug, and the like (not shown). A part of the cooling water pipe 3 is provided with a heat exchanger 4 and a cooling fan 5 for cooling the cooling water. Further, a temperature sensor (temperature detection means) 6 for detecting the temperature of the cooling water is disposed in the cooling water pipe 3.

  A biomass gas supply source 11 for supplying woody biomass gas to the dual fuel engine 1 is provided. Woody biomass gas is supplied from the biomass gas supply source 11 to the dual fuel engine 1 via the first supply line 12. The first supply line 12 is provided with a first control valve 13 capable of controlling whether or not wood biomass is supplied from the biomass gas supply source 11 to the dual fuel engine 1 and the supply amount. The biomass gas supply source 11 includes a gasifier that generates woody biomass gas. The woody biomass gas supplied from the biomass gas supply source 11 to the dual fuel engine 1 does not need to be of high quality and contains tar which is an impurity that adversely affects the dual fuel engine 1 if it is about 100 ppm. Also good. Therefore, in order to significantly reduce the tar content to 10 ppm or less, it is not necessary to provide a special filter device or a high-performance tar reformer on the biomass gas supply source 11 side.

  Further, an LP gas supply source 14 for supplying LP gas to the dual fuel engine 1 is provided. LP gas is supplied from the LP gas supply source 14 to the dual fuel engine 1 via the second supply line 15. The second supply line 15 is provided with a second control valve 16 that can control whether or not LP gas is supplied from the LP gas supply source 14 to the dual fuel engine 1 and the supply amount.

  Further, an air supply source 17 for supplying air to the dual fuel engine 1 is provided. Air is supplied from the air supply source 17 to the dual fuel engine 1 via the third supply line 18. The third supply line 18 is provided with a third control valve 19 that can control whether or not air is supplied from the air supply source 17 to the dual fuel engine 1 and the supply amount.

  The controller (control means) 21 is based on the start and stop commands input from the operation panel 22, the temperature detected by the temperature sensor 6, etc., and the dual fuel engine 1, the first control valve 13, and the second control valve 16. And the operation of the third control valve 19 is controlled.

  Next, details of the control executed by the controller 21 will be described with reference to the flowchart of FIG. 2 and the time chart of FIG.

When an activation command is input from the operation panel 22 (step S1), the second control valve 16 and the third control valve are opened (steps S2 and S3), and LP gas and air are supplied to the dual fuel engine 1. Start up. Then, until the detected temperature T of the temperature sensor 6 becomes _{equal to} or higher than a predetermined set temperature T _set , that is, until the temperature of the dual fuel engine 1 is sufficiently increased and it can be considered that the warm-up operation is finished (step S4). The dual fuel engine 1 is operated using only LP gas as fuel without supplying woody biomass gas from the biomass gas supply source 11 (time t0 to t1 in FIG. 3).

  When the dual fuel engine 1 is started, its temperature is not sufficiently increased and is relatively low. When wood biomass gas is supplied as fuel to the dual fuel engine 1 in this relatively low temperature state, the tar contained in the wood biomass gas in a low viscosity state is the intake valve, exhaust valve, and spark plug of the dual fuel engine 1 It is easy to adhere to etc. However, in the present embodiment, until the end of the warm-up operation after the start of the dual fuel engine 1, by using LP gas not containing tar instead of woody biomass gas as the fuel of the dual fuel engine 1, It is possible to prevent tar from adhering to exhaust valves, spark plugs and the like.

If the detected temperature T of the temperature sensor 6 is equal to or higher than the set temperature T _set (step S4), the first control valve 13 is opened and the second control valve 16 is closed (steps S5, 6). The fuel supplied to the L engine 1 is switched from LP gas to woody biomass gas from the biomass gas supply source 11. Since the warm-up operation has already been completed and the temperature of the dual fuel engine 1 has risen sufficiently, the tar contained in the woody biomass gas hardly adheres to the intake valves, exhaust valves, spark plugs, and the like.

  Until the operation stop command is input from the operation panel 22 (step S7), the woody biomass gas is supplied from the biomass gas supply source 11 to the dual fuel engine 1 (time t1 to t2 in FIG. 3).

When an operation stop command is input from the operation panel 22 (step S7), the first control valve 13 is closed and the second control valve 16 is opened (steps S8, S9), and supplied to the dual fuel engine 1. The fuel to be used is switched from woody biomass gas to LP gas. Further, the timer starts counting (step S10). When the time t measured by the timer reaches a predetermined set time t _set (step S11), the second control valve 16 and the third control valve 19 are closed to cut off the supply of LP gas and air. The dual fuel engine 1 is stopped (time t2 to t3 in FIG. 3).

If the wood biomass gas remains in the cylinder chamber when the dual fuel engine 1 is stopped, the temperature of the remaining wood biomass gas also decreases as the temperature decreases after the operation is stopped. As a result, the viscosity of tar is reduced. Decrease and adhere to the intake valve, exhaust valve, spark plug, etc. However, in the operation control system for an internal combustion engine according to the present invention, the fuel supplied to the dual fuel engine 1 is changed from wood biomass gas to LP gas for a predetermined set time t _set before the dual fuel engine 1 is stopped. Since switching is performed, the woody biomass gas does not remain when the dual fuel engine 1 is stopped. Further, tar and the like adhering during the operation using the recycle gas (time t1 to 2) is cleaned in the operation using the general-purpose fuel (time t2 to t3). Therefore, tar sticking at the time of stop can be prevented.

As described above, in the operation control system for the internal combustion engine according to the present embodiment, from the start of the dual fuel engine 1 to the end of the warm-up operation (time t0 to t1 in FIG. 3) and from the stop of the dual fuel engine 1 During the set time t _set , by supplying LP gas to the dual fuel engine 1 instead of the woody biomass gas containing tar, sticking of tar to the dual fuel engine 1 at the time of start and stop is prevented. is doing. Therefore, without using a special filter or high-performance gas reformer and containing about 100ppm of tar while suppressing the frequency of overhaul of the dual fuel engine 1 to the same level as when using ordinary general-purpose fuel. The dual fuel engine 1 can be operated with woody biomass.

  The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the recycled gas may be a biomass gas other than woody biomass gas, a gas generated from waste tires, or the like, and the general-purpose fuel may be gasoline, light oil, heavy oil, etc. other than LP gas. Depending on the general-purpose fuel used, the dual fuel engine may be operable with two types of gas fuels or may be operable with gas fuels and liquid fuels. Further, regarding the end of the warm-up operation, the controller may determine that the warm-up operation has been completed when a time has elapsed after the dual fuel engine has been started and the temperature can be considered to have sufficiently increased.

1 is a block diagram showing an operation control system of an internal combustion engine system according to an embodiment of the present invention. The flowchart for demonstrating operation | movement of the internal combustion type operation control system which concerns on embodiment of this invention. The typical time chart for explaining operation of the internal-combustion type operation control system concerning the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dual fuel engine 2 Generator 3 Cooling water piping 4 Heat exchanger 5 Cooling fan 6 Temperature sensor 11 Biomass gas supply source 12 1st supply line 13 1st control valve 14 LP gas supply source 15 2nd supply line 16 2nd Control valve 17 Air supply source 18 Third supply line 19 Third control valve 21 Controller 22 Operation panel

Claims (2)

An internal combustion prime mover capable of operating using both recycled gas containing impurities and general-purpose fuel, a recycle gas supply source capable of supplying the recycle gas to the internal combustion prime mover, and supplying the general-purpose fuel to the internal combustion prime mover In an operation control system for an internal combustion engine that includes a possible general-purpose fuel supply source,
From the start of the internal combustion engine to the end of the warm-up operation, only the general-purpose fuel is supplied to the internal combustion engine. After the warm-up operation is completed, the fuel supplied to the internal combustion motor is changed from the general-purpose fuel to the recycle gas. The recycled gas supply source and the universal fuel supply are switched so that the fuel supplied to the internal combustion prime mover is switched from the recycled gas to the universal fuel for a predetermined time before the internal combustion prime mover is stopped. An operation control system for an internal combustion prime mover, comprising control means for controlling fuel supply from a source to the internal combustion prime mover. Temperature detection means for detecting the temperature of the cooling water of the internal combustion motor,
The supply control means determines that the warm-up operation has ended when the coolant temperature detected by the temperature detection means after starting the internal combustion prime mover reaches a preset temperature, and supplies it to the internal combustion prime mover. The operation control system for an internal combustion engine according to claim 1, wherein the fuel to be switched is switched from the general-purpose fuel to the recycle gas.

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