WO2010092945A1 - Gas engine system and method for controlling same - Google Patents

Gas engine system and method for controlling same Download PDF

Info

Publication number
WO2010092945A1
WO2010092945A1 PCT/JP2010/051863 JP2010051863W WO2010092945A1 WO 2010092945 A1 WO2010092945 A1 WO 2010092945A1 JP 2010051863 W JP2010051863 W JP 2010051863W WO 2010092945 A1 WO2010092945 A1 WO 2010092945A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas engine
exhaust
turbine
power recovery
gas
Prior art date
Application number
PCT/JP2010/051863
Other languages
French (fr)
Japanese (ja)
Inventor
哲夫 徳岡
Original Assignee
川崎重工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 川崎重工業株式会社 filed Critical 川崎重工業株式会社
Publication of WO2010092945A1 publication Critical patent/WO2010092945A1/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
    • F02B37/12—Control of the pumps
    • F02B37/18—Control of the pumps by bypassing exhaust from the inlet to the outlet of turbine or to the atmosphere
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
    • F02B37/001—Engines characterised by provision of pumps driven at least for part of the time by exhaust using exhaust drives arranged in parallel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
    • F02B37/004—Engines characterised by provision of pumps driven at least for part of the time by exhaust with exhaust drives arranged in series
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
    • F02B37/12—Control of the pumps
    • F02B37/24—Control of the pumps by using pumps or turbines with adjustable guide vanes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B41/00—Engines characterised by special means for improving conversion of heat or pressure energy into mechanical power
    • F02B41/02—Engines with prolonged expansion
    • F02B41/10—Engines with prolonged expansion in exhaust turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/0002—Controlling intake air
    • F02D41/0007—Controlling intake air for control of turbo-charged or super-charged engines
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • the present invention relates to a gas engine system in which an exhaust turbine for power recovery is attached to a gas engine, and a control method therefor.
  • a gas engine is an internal combustion engine that uses a gas such as LNG (liquefied natural gas) as fuel, and has the advantage that the amount of CO 2 contained in the exhaust gas is small, and has recently been put into practical use as a driving means for generators and the like. It is being advanced.
  • LNG liquefied natural gas
  • a turbo compound system is a system that can effectively utilize surplus exhaust energy in a gas engine.
  • an exhaust turbine 21 for power recovery is attached to the gas engine 1 to which the supercharger 10 is connected, and surplus exhaust gas supplied to the turbine 11 of the supercharger 10 is obtained.
  • the exhaust energy is sent to the exhaust turbine 21 through the branch passage 3 to effectively recover the exhaust energy.
  • a generator 22 is connected to the exhaust turbine 21 as shown in FIG. 5, or a crankshaft of the gas engine 1 is connected via a speed reducer 23 as shown in FIG. In this way, the recovered power is converted into electric power (FIG. 5) or returned to the gas engine (FIG. 6).
  • the air-fuel ratio ratio of air supply amount to fuel amount, mixing ratio
  • the air supply amount is determined by engine output (for example, power generation amount). It is necessary to control accurately according to the amount of fuel determined by. However, even if the engine output is always constant, the appropriate air supply amount changes according to changes in ambient conditions such as the atmospheric temperature. Therefore, in order to properly control the air supply amount, it is necessary to adjust the exhaust amount supplied to the turbine of the supercharger. For this reason, the surplus part which is not sent to the turbine of a supercharger generate
  • the supercharger 10 includes a turbine 11 and a blower 12, and the blower 12 is rotated by the turbine 11 driven by the exhaust energy, whereby the necessary air supply to the gas engine 1 is increased.
  • Supply pressurize and supply
  • reference numeral 8 in the figure is a generator driven by the gas engine 1, 6 is an air cooler for cooling the supply air, and V3 is a throttle valve for controlling the amount of excess exhaust.
  • the turbo compound engine 1 ′ includes a low pressure turbine 21 ′ together with a high pressure turbine 11 ′ of the supercharger 10 ′, and exhaust of the engine 1 ′ is discharged from the high pressure turbine 11 ′ and the low pressure turbine 21 ′.
  • the exhaust energy is recovered by continuously flowing it.
  • 5' denotes an air supply passage
  • a throttle valve V3 is provided in the branch flow path 3 in order to control the exhaust amount supplied to the turbine 11 of the supercharger 10, and hence the surplus exhaust amount.
  • a so-called throttle loss L occurs, and the effective use of exhaust energy is hindered.
  • the entire amount of exhaust gas is supplied to the high-pressure turbine (supercharger turbine) 11 ', and then the exhaust gas is supplied to the low-pressure turbine 21'.
  • the energy recovery rate of the low-pressure turbine is low and the exhaust energy is low. It is difficult to significantly improve the recovery efficiency.
  • the system of FIG. 7 that sends the entire amount of exhaust gas to the turbine 11 ′ of the supercharger 10 ′ cannot be applied smoothly to a gas engine with a narrow allowable air-fuel ratio range as described above.
  • An object of the present invention is to solve the above problems and to obtain a gas engine system and a control method therefor that can make maximum use of exhaust energy in a turbo compound system (gas engine system) using a gas engine. To do.
  • the present invention has a gas engine and a supercharging turbine that is driven by being supplied with exhaust gas from the gas engine, and the supercharging that supercharges the gas engine by driving the supercharging turbine. And a power recovery exhaust turbine connected to the gas engine and driven by a part of the exhaust gas supplied from the gas engine to the turbocharger turbine.
  • the exhaust turbine is a gas engine system having variable nozzles each having an adjustable opening.
  • the gas engine system of the present invention is -A gas engine with a turbocharger is equipped with an exhaust turbine for power recovery, and the exhaust from the gas engine is supplied separately to the turbocharger turbocharger and the power recovery exhaust turbine described above.
  • -Each of the supercharging turbine and the power recovery exhaust turbine of the supercharger has a variable nozzle capable of adjusting the opening (that is, changing the nozzle cross-sectional area).
  • the exhaust of the gas engine is supplied separately (that is, in parallel) to the supercharging turbine and the power recovery exhaust turbine of the supercharger.
  • the exhaust energy can be effectively recovered by the two turbines.
  • the two turbines each have variable nozzles whose opening degrees can be adjusted, there is no need to use a throttle valve that causes a throttle loss. Therefore, the energy recovered by each turbine can be increased. That is, since the exhaust turbine for power recovery has the variable nozzle, power recovery from surplus exhaust can be made more efficient without causing a throttle loss.
  • the turbocharger turbocharger also has a variable nozzle, so the amount of exhaust flowing to the power recovery exhaust turbine can be increased or decreased to optimize the output of the entire system including the gas engine and power recovery exhaust turbine. Can be realized.
  • the present invention is a gas engine system characterized in that a generator is connected to the gas engine, and another generator different from the generator or a gas engine is connected to the power recovery exhaust turbine. .
  • the gas engine is connected to the generator and the exhaust turbine for power recovery is connected to another generator or gas engine.
  • the system shown in FIGS. 1 and 2 is an example.
  • the output of the gas engine does not fluctuate greatly in a short time, and therefore quick control is not necessary for efficiently recovering exhaust energy. For this reason, when these are connected in order for a gas engine to drive a generator, the opening degree adjustment of each variable nozzle in said two turbines can be performed comparatively easily.
  • the exhaust turbine for power recovery is connected to other generators or gas engines and drives them, the main output can be collected as electric power, and energy can be obtained in an easy-to-use form.
  • an exhaust passage for supplying exhaust gas from the gas engine to the supercharging turbine is connected between the gas engine and the supercharging turbine, and the exhaust passage is connected to the exhaust turbine for power recovery.
  • the first branch channel is branched, and the second branch channel capable of releasing the exhaust gas flowing through the exhaust channel to the atmosphere is branched.
  • the first branch channel can be opened and closed with respect to the first branch channel.
  • a gas engine system characterized in that a first stop valve is provided, and a second stop valve capable of opening and closing the second branch channel is provided in the second branch channel.
  • a first stop valve is provided in the exhaust flow path (first branch flow path) to the power recovery exhaust turbine separated from the exhaust gas reaching the supercharge turbine of the supercharger.
  • the flow path (second branch flow path) including the second stop valve that can release part of the exhaust gas to the atmosphere when the 1 stop valve is fully closed is connected to the flow path of the exhaust gas from the gas engine.
  • the system of FIG. 3 is an example.
  • the opening adjustment of each variable nozzle of the turbine of the supercharger and the exhaust turbine for power recovery is performed.
  • a predetermined air-fuel ratio is realized in the gas engine,
  • the total output of the gas engine and power recovery exhaust turbine increases. It is preferable to be performed as follows.
  • the amount of exhaust gas supplied to the power recovery exhaust turbine is always 10% or more of the total displacement of the gas engine regardless of the outside temperature (and therefore regardless of the season). It is preferable that the opening degree of the variable nozzle is adjusted.
  • the present invention greatly changes such a conventional exhaust amount distribution. For example, more than 10% of the total exhaust amount is supplied to the exhaust turbine for power recovery in the winter. This brings about the following effects. That is, ⁇ Active energy recovery can be performed in a power recovery exhaust turbine that always supplies more than 10% of the total displacement, so the total output of the gas engine and power recovery exhaust turbine is maximized (optimum). This makes it possible to efficiently use exhaust energy. ⁇ The exhaust turbine for power recovery, which has not been used in the past when exhaust is not supplied, such as in summer, can be effectively used continuously regardless of the season, and equipment costs can be recovered early.
  • the pressure of the exhaust gas in the gas engine is equivalent to the pressure of the supply air (same as or slightly lower than the supply air pressure). It is preferable to be performed as follows.
  • the exhaust pressure in the gas engine increases, while the flow velocity in the turbocharger turbocharger increases.
  • the energy can be increased.
  • the amount of exhaust gas supplied to the power recovery exhaust turbine can be increased.
  • the variable nozzle of the turbocharger turbocharger is throttled until the exhaust pressure becomes equal to the supply air pressure, the amount of exhaust supplied to the power recovery exhaust turbine is about 20% of the total exhaust (summer season) 20% and 30% in winter). For this reason, the above-described effect of increasing the total output of the system can be made remarkable. If the exhaust pressure exceeds the supply air pressure, the exhaust gas may flow back into the gas engine and the gas engine may become unstable, but the exhaust pressure is the same as or slightly higher than the supply air pressure. Since it is low, there is no inconvenience in the operation of the gas engine.
  • the adjustment of the opening of the variable nozzle in the power recovery exhaust turbine maximizes the output from the exhaust to the power recovery exhaust turbine (separated from the exhaust to the turbocharger turbocharger). Preferably, it is done.
  • variable nozzle By making maximum use of such functions of the variable nozzle, as described above, the energy recovery in the power recovery exhaust turbine is increased, and the total output of the gas engine and the power recovery exhaust turbine is maximized. It becomes possible.
  • the exhaust energy of the gas engine can be efficiently recovered in both the turbocharger turbocharger and the power recovery exhaust turbine.
  • the main output by the system is collected as electric power so that the gas engine drives the generator.
  • energy recovery can be easily controlled, and energy can be easily obtained.
  • the gas engine can be smoothly operated even when the exhaust turbine for power recovery and its variable nozzle do not function normally due to a failure or the like.
  • FIG. 1 to 3 show a gas engine system as an embodiment of the present invention. Each of them shows a kind of turbo compound system (TCS), and an exhaust turbine 21 for power recovery is attached to the gas engine 1.
  • TCS turbo compound system
  • the generator 8 is connected to the output shaft of the gas engine 1.
  • a supercharger 10 is connected to the gas engine 1 through an exhaust passage 2 and an air supply passage 5, and a fuel supply pipe 7 that sends LNG as fuel gas to the gas engine 1 is connected.
  • the supercharger 10 has a turbocharger turbine 11 and a blower 12 provided on one axis, and rotates the turbocharger 11 by the energy of the exhaust gas from the gas engine 1 supplied from the exhaust passage 2. Then, the blower 12 is driven with the motive power, and the gas engine 1 is supercharged through the air supply passage 5.
  • the air supply channel 5 is provided with an air cooler 6 for cooling the supply air.
  • the first branch flow path 3 for exhaust gas is connected so as to branch from the exhaust flow path 2 of the gas engine 1, and the power recovery exhaust turbine 21 is provided at the end thereof. That is, in the gas engine system of FIGS. 1 to 3, the exhaust from the gas engine 1 is sent to the exhaust passage 2 to drive the supercharger 10 and the first branch passage 3 branched from the exhaust passage 2. Then, the exhaust gas from the gas engine 1 is diverted to drive the exhaust turbine 21 for power recovery.
  • a generator 22 is connected to the exhaust turbine 21 for power recovery, and energy is recovered from the shunted exhaust as electric power.
  • the output shaft of the power recovery exhaust turbine 21 is connected to the output shaft of the gas engine 1 via the speed reducer 23, and a part of the energy of the divided exhaust gas is transferred to the gas engine 1. I'm trying to reduce it.
  • a supercharger 10 By operating the variable nozzle 11a of the supercharging turbine 11 of the supercharger 10 to make the nozzle area appropriate, A supercharger 10 supercharges the gas engine 1 with an appropriate amount of air supply according to the amount of fuel to achieve a predetermined air-fuel ratio suitable for the operation of the gas engine 1; The amount of exhaust from the first branch flow path 3 to the power recovery exhaust turbine 21 is increased or decreased to control the total output of the gas engine 1 and the power recovery exhaust turbine 21 to the maximum. . If the variable nozzle 11a of the supercharging turbine 11 is throttled, the exhaust pressure of the gas engine 1 may increase and the output of the gas engine 1 may decrease. However, the total value with the output of the power recovery exhaust turbine 21 is Because it increases, it is not a problem.
  • variable nozzle 21a of the power recovery exhaust turbine 21 adjusts the opening so as to maximize the output by the exhaust gas sent to the first branch flow path 3. This is to make maximum use of such a function of the variable nozzle 21a not provided in the throttle valve.
  • the amount of exhaust gas supplied to the power recovery exhaust turbine 21 is 10% or more of the total displacement of the gas engine 1 even in summer (about 20% or more in winter). ), The opening degree of each of the variable nozzles 11a and 21a is adjusted. If it does in this way, energy recovery in the exhaust turbine 21 for power recovery can be made active, and the total output of the gas engine 1 and the exhaust turbine 21 for power recovery can be increased easily.
  • the opening degree of the variable nozzle 11a of the turbocharger 11 of the supercharger 10 is set so that the exhaust pressure of the gas engine 1 is equal to the supply pressure (supply pressure). Until it is equal to or slightly lower than If the variable nozzle 11a of the turbocharging turbine 11 is throttled in this way, the amount of exhaust gas supplied to the power recovery exhaust turbine 21 can be increased to more than the level of d), and the total output of the system can be further increased. it can.
  • the gas engine system of FIG. 3 is based on the system of FIG. 2, but the following configuration is added to enhance practicality. That is, the first stop valve V1 is provided in the first branch flow path 3 of the exhaust gas that reaches the power recovery exhaust turbine 21, and the exhaust gas flow path 2 that leads to the supercharge turbine 11 of the supercharger 10 leads to the atmosphere. Another second branch flow path 4 is connected, and the second branch flow path 4 is provided with a second stop valve V2.
  • This system can advantageously cope with a case where the exhaust turbine 21 for power recovery or its variable nozzle 21a breaks down. That is, first, during normal operation without failure, the first stop valve V1 of the first branch flow path 3 is fully opened and the second stop valve V2 of the second branch flow path 4 is fully closed. Operate the system in the same system. On the other hand, if a failure occurs in the power recovery exhaust turbine 21 or the like, the first stop valve V1 is fully closed to stop the supply of exhaust gas to the power recovery exhaust turbine 21 (further, the speed reducer 23 and the power recovery At the same time, the degree of opening of the second stop valve V2 is adjusted, and surplus exhaust not used in the supercharger 10 is discharged from the second branch flow path 4 into the atmosphere. While the power recovery exhaust turbine 21 is not used, the energy recovery efficiency is inevitably lowered, but repair of the power recovery exhaust turbine 21 and the like can proceed while the gas engine 1 continues to operate smoothly.
  • the output shaft of the power recovery exhaust turbine 21 may be connected to a generator as in the example of FIG. In such a case as well, it is possible to advantageously cope with the case where the variable nozzle 21a breaks down.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Supercharger (AREA)

Abstract

The energy of exhaust gas is best utilized in a turbo compound system (gas engine system) in which a gas engine is used. The gas engine system comprises the gas engine (1) and a supercharger (10) which has a turbine (11) for supercharging driven by the exhaust gas supplied from the gas engine (1) thereto and which supercharges a supply air to the gas engine (1) when the turbine (11) for supercharging is driven.  An exhaust gas turbine (12) for power recovery, which is driven when a part of the exhaust gas is supplied from the gas engine (1) to the turbine (11) for supercharging, is connected to the gas engine (1).  The turbine (11) for supercharging and the exhaust gas turbine (12) for power recovery comprise respective variable nozzles with adjustable openings.

Description

ガスエンジンシステムおよびその制御方法Gas engine system and control method thereof
　本発明は、ガスエンジンに動力回収用排気タービンが付設されたガスエンジンシステムとその制御方法に関するものである。 The present invention relates to a gas engine system in which an exhaust turbine for power recovery is attached to a gas engine, and a control method therefor.
　ガスエンジンは、ＬＮＧ（液化天然ガス）等のガスを燃料とする内燃機関であり、排気中に含まれるCO2量が少ない等の利点を有し、発電機等の駆動手段として近年実用化が進められている。 A gas engine is an internal combustion engine that uses a gas such as LNG (liquefied natural gas) as fuel, and has the advantage that the amount of CO 2 contained in the exhaust gas is small, and has recently been put into practical use as a driving means for generators and the like. It is being advanced.
　ガスエンジンにおける余剰排気エネルギーを有効活用できるシステムとして、ターボコンパウンドシステム（ＴＣＳ）がある。このシステムは、図５のように、過給機１０が接続されたガスエンジン１に、動力回収用の排気タービン２１が付設され、過給機１０のタービン１１に供給された排気の余剰分を、分岐流路３を通して排気タービン２１に送ることにより排気エネルギーの有効回収を図るシステムである。排気タービン２１には図５のように発電機２２が接続され、または図６のように減速機２３を介してガスエンジン１のクランク軸が接続されている。このようにして、回収した動力を電力に変換したり（図５）ガスエンジンに還元したり（図６）している。 A turbo compound system (TCS) is a system that can effectively utilize surplus exhaust energy in a gas engine. In this system, as shown in FIG. 5, an exhaust turbine 21 for power recovery is attached to the gas engine 1 to which the supercharger 10 is connected, and surplus exhaust gas supplied to the turbine 11 of the supercharger 10 is obtained. In this system, the exhaust energy is sent to the exhaust turbine 21 through the branch passage 3 to effectively recover the exhaust energy. A generator 22 is connected to the exhaust turbine 21 as shown in FIG. 5, or a crankshaft of the gas engine 1 is connected via a speed reducer 23 as shown in FIG. In this way, the recovered power is converted into electric power (FIG. 5) or returned to the gas engine (FIG. 6).
　ガスエンジンでは、円滑な運転を行うための空燃比（給気量と燃料量との比。混合比）が特定の狭い範囲に限られるため、給気量は、エンジン出力（例えば、発電量）で定まる燃料量に応じて正確に制御される必要がある。しかしながら、エンジン出力が常に一定であっても、大気温度など周囲の条件の変化に応じて適正な給気量は変化する。そこで、給気量を適正に制御するためには、過給機のタービンに供給される排気量を調整する必要がある。このため、ガスエンジンからの排気のうち、過給機のタービンには送られない余剰分が発生する。そこで、図５および図６に示すターボコンパウンドシステムは、そうした余剰排気のエネルギーを排気タービン２１で回収するようになっている。 In a gas engine, since the air-fuel ratio (ratio of air supply amount to fuel amount, mixing ratio) for smooth operation is limited to a specific narrow range, the air supply amount is determined by engine output (for example, power generation amount). It is necessary to control accurately according to the amount of fuel determined by. However, even if the engine output is always constant, the appropriate air supply amount changes according to changes in ambient conditions such as the atmospheric temperature. Therefore, in order to properly control the air supply amount, it is necessary to adjust the exhaust amount supplied to the turbine of the supercharger. For this reason, the surplus part which is not sent to the turbine of a supercharger generate | occur | produces among the exhaust_gas | exhaustion from a gas engine. Therefore, in the turbo compound system shown in FIGS. 5 and 6, the energy of such surplus exhaust is recovered by the exhaust turbine 21.
　なお、図示の通り過給機１０は、タービン１１とブロア１２とを有し、排気エネルギーで駆動されるタービン１１によってブロア１２を回転させ、このことにより、ガスエンジン１に必要な給気を過給（加圧して供給）する。そのほか、図中の符号８は、ガスエンジン１が駆動する発電機、同６は給気を冷却する空気冷却器、同Ｖ３は余剰排気の量をコントロールする絞り弁である。 As shown in the figure, the supercharger 10 includes a turbine 11 and a blower 12, and the blower 12 is rotated by the turbine 11 driven by the exhaust energy, whereby the necessary air supply to the gas engine 1 is increased. Supply (pressurize and supply). In addition, reference numeral 8 in the figure is a generator driven by the gas engine 1, 6 is an air cooler for cooling the supply air, and V3 is a throttle valve for controlling the amount of excess exhaust.
　ガスエンジンに限らないターボコンパウンドシステムに関しては、図７に示すものが特許文献１に記載されている。図７の例では、ターボコンパウンドエンジン１’が、過給機１０’の高圧タービン１１’とともに低圧タービン２１’を具備しており、エンジン１’の排気をそれら高圧タービン１１’と低圧タービン２１’とに連続して流すことにより排気エネルギーの回収を行う。なお、図７において、符号２’は排気流路、同５’は給気流路、同１２’は過給機１０’のブロアである。 As for a turbo compound system that is not limited to a gas engine, the one shown in FIG. In the example of FIG. 7, the turbo compound engine 1 ′ includes a low pressure turbine 21 ′ together with a high pressure turbine 11 ′ of the supercharger 10 ′, and exhaust of the engine 1 ′ is discharged from the high pressure turbine 11 ′ and the low pressure turbine 21 ′. The exhaust energy is recovered by continuously flowing it. In FIG. 7, reference numeral 2 'denotes an exhaust passage, 5' denotes an air supply passage, and 12 'denotes a blower of the supercharger 10'.
特開２００７－２２４８０２号公報JP 2007-224802 A
　図５および図６の例では、過給機１０のタービン１１に供給する排気量、したがって余剰の排気量を制御するために、分岐流路３に絞り弁Ｖ３が設けられている。しかし、このように絞り弁Ｖ３によって余剰の排気量を制御する場合には、いわゆる絞り損失Ｌが発生し、排気エネルギーの有効活用が阻害される。 5 and FIG. 6, a throttle valve V3 is provided in the branch flow path 3 in order to control the exhaust amount supplied to the turbine 11 of the supercharger 10, and hence the surplus exhaust amount. However, when the excessive exhaust amount is controlled by the throttle valve V3 in this way, a so-called throttle loss L occurs, and the effective use of exhaust energy is hindered.
　図７の例では、排気の全量が高圧タービン（過給機のタービン）１１’に供給され、さらにその後に排気が低圧タービン２１’に供給される。しかし、高圧タービン１１’と低圧タービン２１’とがこのように直列的に接続されて排気が双方のタービン１１’、２１’を経由するシステムでは、低圧タービンのエネルギー回収率が低く、排気エネルギーの回収効率を大幅に改善することは難しい。また、排気の全量を過給機１０’のタービン１１’に送る図７のシステムは、上述のように空燃比の許容幅が狭いガスエンジンには円滑に適用することができないと考えられる。 In the example of FIG. 7, the entire amount of exhaust gas is supplied to the high-pressure turbine (supercharger turbine) 11 ', and then the exhaust gas is supplied to the low-pressure turbine 21'. However, in a system in which the high-pressure turbine 11 ′ and the low-pressure turbine 21 ′ are connected in series as described above and the exhaust gas passes through both the turbines 11 ′ and 21 ′, the energy recovery rate of the low-pressure turbine is low and the exhaust energy is low. It is difficult to significantly improve the recovery efficiency. Further, it is considered that the system of FIG. 7 that sends the entire amount of exhaust gas to the turbine 11 ′ of the supercharger 10 ′ cannot be applied smoothly to a gas engine with a narrow allowable air-fuel ratio range as described above.
　本発明は、以上のような課題を解決し、ガスエンジンによるターボコンパウンドシステム（ガスエンジンシステム）において排気のエネルギーを最大限に活用することができるガスエンジンシステムおよびその制御方法を得ることを目的とするものである。 SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to obtain a gas engine system and a control method therefor that can make maximum use of exhaust energy in a turbo compound system (gas engine system) using a gas engine. To do.
　本発明は、ガスエンジンと、ガスエンジンからの排気が供給されて駆動される過給用タービンを有し、この過給用タービンが駆動されることによりガスエンジンに給気を過給する過給機と、ガスエンジンに接続され、このガスエンジンから過給用タービンに供給される排気の一部が供給されて駆動される動力回収用排気タービンと、を備え、過給用タービンおよび動力回収用排気タービンは、開度調整可能な可変ノズルをそれぞれ有していることを特徴とするガスエンジンシステムである。 The present invention has a gas engine and a supercharging turbine that is driven by being supplied with exhaust gas from the gas engine, and the supercharging that supercharges the gas engine by driving the supercharging turbine. And a power recovery exhaust turbine connected to the gas engine and driven by a part of the exhaust gas supplied from the gas engine to the turbocharger turbine. The exhaust turbine is a gas engine system having variable nozzles each having an adjustable opening.
　すなわち、本発明のガスエンジンシステムは、
　・　過給機を有するガスエンジンに動力回収用排気タービンが付設されていて、ガスエンジンの排気が、過給機の過給用タービンと上記の動力回収用排気タービンとに分けて供給されること、および、
　・　上記した過給機の過給用タービンと動力回収用排気タービンとがそれぞれ、開度調整（すなわちノズル断面積の変更）が可能な可変ノズルを有するものであること――を特徴とする。 That is, the gas engine system of the present invention is
-A gas engine with a turbocharger is equipped with an exhaust turbine for power recovery, and the exhaust from the gas engine is supplied separately to the turbocharger turbocharger and the power recovery exhaust turbine described above. ,and,
-Each of the supercharging turbine and the power recovery exhaust turbine of the supercharger has a variable nozzle capable of adjusting the opening (that is, changing the nozzle cross-sectional area).
　このようなガスエンジンシステムでは、まず、ガスエンジンの排気が過給機の過給用タービンと動力回収用排気タービンとに分けて（つまり並列的に）供給されることから、図５および図６の例と同様、排気のエネルギーを上記二つのタービンで有効に回収することができる。 In such a gas engine system, first, the exhaust of the gas engine is supplied separately (that is, in parallel) to the supercharging turbine and the power recovery exhaust turbine of the supercharger. As in the example, the exhaust energy can be effectively recovered by the two turbines.
　しかもこのシステムでは、上記二つのタービンがそれぞれ開度調整可能な可変ノズルを有するため、絞り損失が生じる絞り弁を使用する必要がない。このめ、各タービンで回収するエネルギーを増大させることができる。すなわち、動力回収用排気タービンが可変ノズルを有するので、絞り損失を生じさせることなく余剰排気からの動力回収を効率化することができる。また、過給機の過給用タービンも可変ノズルを有するので、動力回収用排気タービンへ流れる排気の量を増減させて、ガスエンジンと動力回収用排気タービンとを含むシステム全体での出力を最適化することが可能となる。 Moreover, in this system, since the two turbines each have variable nozzles whose opening degrees can be adjusted, there is no need to use a throttle valve that causes a throttle loss. Therefore, the energy recovered by each turbine can be increased. That is, since the exhaust turbine for power recovery has the variable nozzle, power recovery from surplus exhaust can be made more efficient without causing a throttle loss. The turbocharger turbocharger also has a variable nozzle, so the amount of exhaust flowing to the power recovery exhaust turbine can be increased or decreased to optimize the output of the entire system including the gas engine and power recovery exhaust turbine. Can be realized.
　また、本発明は、ガスエンジンに発電機が接続され、動力回収用排気タービンに、発電機とは異なる他の発電機、またはガスエンジンが接続されていることを特徴とするガスエンジンシステムである。 Further, the present invention is a gas engine system characterized in that a generator is connected to the gas engine, and another generator different from the generator or a gas engine is connected to the power recovery exhaust turbine. .
　すなわち、ガスエンジンが発電機に接続されていて、動力回収用排気タービンが、他の発電機またはガスエンジンに接続されていることが、特に好ましい。図１および図２に示すシステムがその例である。 That is, it is particularly preferable that the gas engine is connected to the generator and the exhaust turbine for power recovery is connected to another generator or gas engine. The system shown in FIGS. 1 and 2 is an example.
　通常はガスエンジンの出力が短時間に大きく変動することがなく、したがって排気エネルギーを効率的に回収するうえで迅速な制御は必要でない。このため、ガスエンジンが発電機を駆動するためにこれらが接続されている場合、上記二つのタービンにおける各可変ノズルの開度調整を比較的容易に行うことができる。そして動力回収用排気タービンが他の発電機またはガスエンジンに接続されていてそれらを駆動する場合、主要な出力を電力としてまとめることができ、利用しやすい形でエネルギーを得ることができる。 Normally, the output of the gas engine does not fluctuate greatly in a short time, and therefore quick control is not necessary for efficiently recovering exhaust energy. For this reason, when these are connected in order for a gas engine to drive a generator, the opening degree adjustment of each variable nozzle in said two turbines can be performed comparatively easily. When the exhaust turbine for power recovery is connected to other generators or gas engines and drives them, the main output can be collected as electric power, and energy can be obtained in an easy-to-use form.
　また、本発明は、ガスエンジンと過給用タービンとの間に、ガスエンジンから過給用タービンに排気を供給する排気流路が接続され、排気流路から、動力回収用排気タービンに接続された第１分岐流路が分岐するとともに、排気流路を流れる排気を大気に放出可能な第２分岐流路が分岐しており、第１分岐流路に、第１分岐流路を開閉可能な第１ストップ弁が設けられ、第２分岐流路に、第２分岐流路を開閉可能な第２ストップ弁が設けられていることを特徴とするガスエンジンシステムである。 In the present invention, an exhaust passage for supplying exhaust gas from the gas engine to the supercharging turbine is connected between the gas engine and the supercharging turbine, and the exhaust passage is connected to the exhaust turbine for power recovery. The first branch channel is branched, and the second branch channel capable of releasing the exhaust gas flowing through the exhaust channel to the atmosphere is branched. The first branch channel can be opened and closed with respect to the first branch channel. A gas engine system characterized in that a first stop valve is provided, and a second stop valve capable of opening and closing the second branch channel is provided in the second branch channel.
　すなわち、過給機の過給用タービンに至る排気から分けられた動力回収用排気タービンに至る排気の流路（第１分岐流路）に、第１ストップ弁が設けられているとともに、この第１ストップ弁が全閉にされたとき排気の一部を大気に放出できる第２ストップ弁を含む流路（第２分岐流路）が、ガスエンジンからの排気の流路に接続されていることが、更に好ましい。たとえば図３のシステムがその例である。 That is, a first stop valve is provided in the exhaust flow path (first branch flow path) to the power recovery exhaust turbine separated from the exhaust gas reaching the supercharge turbine of the supercharger. The flow path (second branch flow path) including the second stop valve that can release part of the exhaust gas to the atmosphere when the 1 stop valve is fully closed is connected to the flow path of the exhaust gas from the gas engine. Is more preferable. For example, the system of FIG. 3 is an example.
　このようなガスエンジンシステムでは、動力回収用排気タービン（またはその可変ノズル等）が故障等によって正常に機能しない場合にも、ガスエンジンを円滑に運転することができる。すなわち、通常は第１ストップ弁を全開にし第２ストップ弁を全閉にしてシステムを運転するが、動力回収用排気タービンが故障等した場合には、第１ストップ弁を全閉にして動力回収用排気タービンに排気が供給されないようにし、第２ストップ弁の開度を調整して余剰の排気が大気中に適宜放出される。そのようにすれば、動力回収用排気タービンを修理する間にも、過給機の過給用タービンを適切に駆動してガスエンジンの円滑な運転を継続することができる。 In such a gas engine system, even when a power recovery exhaust turbine (or its variable nozzle or the like) does not function normally due to a failure or the like, the gas engine can be operated smoothly. That is, normally, the system is operated with the first stop valve fully open and the second stop valve fully closed, but when the power recovery exhaust turbine fails, the first stop valve is fully closed to recover the power. Excess exhaust is appropriately discharged into the atmosphere by adjusting the opening of the second stop valve so that the exhaust is not supplied to the exhaust turbine. By doing so, the smooth operation of the gas engine can be continued by appropriately driving the turbocharging turbine of the supercharger while repairing the power recovery exhaust turbine.
　また、本発明のガスエンジンシステムおよびその制御方法では、過給機のタービンおよび動力回収用排気タービンの各可変ノズルの開度調整が、
　・　ガスエンジンにおいて所定の空燃比が実現するとともに、
　・　上記したガスエンジンおよび動力回収用排気タービンによる出力の合計値が増大する、
　ように行われることが好ましい。 Further, in the gas engine system and the control method thereof according to the present invention, the opening adjustment of each variable nozzle of the turbine of the supercharger and the exhaust turbine for power recovery is performed.
・ A predetermined air-fuel ratio is realized in the gas engine,
The total output of the gas engine and power recovery exhaust turbine increases.
It is preferable to be performed as follows.
　ガスエンジンシステムをこのように制御すれば、空燃比の許容幅の狭いガスエンジンを円滑に運転できるとともに、排気のエネルギーを効率的に活用することができる。先に紹介した図５および図６の例では、全ての排気のうち過給機のタービンに供給される排気を除いた余剰排気からエネルギーの回収を図るにすぎなかったが、本発明によれば、ガスエンジンおよび動力回収用排気タービンによる出力の合計値が最大になることを目指し、ガスエンジンの出力を多少低下させてでも動力回収用排気タービンにおいて積極的なエネルギー回収が行われる。 By controlling the gas engine system in this way, it is possible to smoothly operate a gas engine having a narrow allowable range of air-fuel ratio and to efficiently use exhaust energy. In the example of FIG. 5 and FIG. 6 introduced above, energy is merely recovered from the surplus exhaust gas except for the exhaust gas supplied to the turbocharger turbine among all the exhaust gases. With the aim of maximizing the total output of the gas engine and the power recovery exhaust turbine, positive energy recovery is performed in the power recovery exhaust turbine even if the output of the gas engine is slightly reduced.
　また、特に、動力回収用排気タービンへ供給される排気の量が、外気温にかかわらず（したがって季節等をも問わず）、常にガスエンジンの全排気量の１０％以上となるように、各可変ノズルの開度調整が行われることが好ましい。 In particular, the amount of exhaust gas supplied to the power recovery exhaust turbine is always 10% or more of the total displacement of the gas engine regardless of the outside temperature (and therefore regardless of the season). It is preferable that the opening degree of the variable nozzle is adjusted.
　ここで、図５および図６に示す従来のシステムは、過給機の過給用タービンに供給された排気を除く余剰排気が動力回収用排気タービンに供給されるものであった。したがって、給気の過給に必要なエネルギーが比較的少ない冬季には、動力回収用排気タービンに供給される排気の量が全排気量の１０％程度ある一方、過給に多めのエネルギーが必要な夏季には動力回収用排気タービンへの排気量がほとんどゼロになるよう設定されていた。 Here, in the conventional system shown in FIGS. 5 and 6, surplus exhaust gas except for the exhaust gas supplied to the supercharging turbine of the supercharger is supplied to the power recovery exhaust turbine. Therefore, in winter when the amount of energy required for supercharging the supply air is relatively small, the amount of exhaust supplied to the exhaust turbine for power recovery is about 10% of the total displacement, while more energy is required for supercharging. During the summer months, the amount of exhaust to the exhaust turbine for power recovery was set to almost zero.
　本発明は、そうした従来の排気量配分を大きく変更するものであり、たとえば夏季でも全排気量の１０％以上、冬季には更に多くの排気を動力回収用排気タービンに供給する。このようにすると次のような作用効果がもたらされる。すなわち、
　・　常に全排気量の１０％以上が供給される動力回収用排気タービンにおいて積極的なエネルギー回収を行うことができるので、ガスエンジンおよび動力回収用排気タービンによる出力の合計値を最大（最適）にするという、排気エネルギーの効率的な活用を行うことができる。
　・　夏季など排気が供給されない時期には従来使用されることがなかった動力回収用排気タービンを、季節を問わず連続して有効活用することができ、設備コストの早期回収が図れる。 The present invention greatly changes such a conventional exhaust amount distribution. For example, more than 10% of the total exhaust amount is supplied to the exhaust turbine for power recovery in the winter. This brings about the following effects. That is,
・ Active energy recovery can be performed in a power recovery exhaust turbine that always supplies more than 10% of the total displacement, so the total output of the gas engine and power recovery exhaust turbine is maximized (optimum). This makes it possible to efficiently use exhaust energy.
・ The exhaust turbine for power recovery, which has not been used in the past when exhaust is not supplied, such as in summer, can be effectively used continuously regardless of the season, and equipment costs can be recovered early.
　また、過給機の過給用タービンの可変ノズルの開度調整は、特に、ガスエンジンにおける排気の圧力が給気の圧力と同等（給気圧力と同一か、それよりやや低い程度）になるように行われることが好ましい。 In addition, when adjusting the opening of the variable nozzle of the turbocharger of the turbocharger, in particular, the pressure of the exhaust gas in the gas engine is equivalent to the pressure of the supply air (same as or slightly lower than the supply air pressure). It is preferable to be performed as follows.
　過給機の過給用タービンの可変ノズルの開度を強めに絞ってノズル面積を小さくすると、ガスエンジンにおける排気の圧力が高くなる一方、過給機の過給用タービン内の流速を上げてそのエネルギーを高めることができる。このことにより、動力回収用排気タービンに供給される排気の量を増やすことができる。排気の圧力が給気の圧力と同等になるまで過給機の過給用タービンの可変ノズルを絞ると、動力回収用排気タービンへ供給される排気の量を全排気量の２０％程度（夏季で２０％、冬季で３０％の程度）以上にすることができる。そしてそのために、システムの合計出力を増やすという上記の作用効果を顕著にすることができる。なお、排気の圧力が給気の圧力を超えてしまうと排気がガスエンジン内に逆流することがありガスエンジンが不安定になりやすいが、排気の圧力が給気の圧力と同一かそれよりやや低いため、ガスエンジンの運転に不都合は生じない。 If the nozzle area is reduced by narrowing the opening of the variable nozzle of the turbocharger turbocharger, the exhaust pressure in the gas engine increases, while the flow velocity in the turbocharger turbocharger increases. The energy can be increased. As a result, the amount of exhaust gas supplied to the power recovery exhaust turbine can be increased. When the variable nozzle of the turbocharger turbocharger is throttled until the exhaust pressure becomes equal to the supply air pressure, the amount of exhaust supplied to the power recovery exhaust turbine is about 20% of the total exhaust (summer season) 20% and 30% in winter). For this reason, the above-described effect of increasing the total output of the system can be made remarkable. If the exhaust pressure exceeds the supply air pressure, the exhaust gas may flow back into the gas engine and the gas engine may become unstable, but the exhaust pressure is the same as or slightly higher than the supply air pressure. Since it is low, there is no inconvenience in the operation of the gas engine.
　また、動力回収用排気タービンにおける可変ノズルの開度調整は、動力回収用排気タービンに至る排気（過給機の過給用タービンに至る排気と分けられたもの）による出力を最大化するように行われることが好ましい。 In addition, the adjustment of the opening of the variable nozzle in the power recovery exhaust turbine maximizes the output from the exhaust to the power recovery exhaust turbine (separated from the exhaust to the turbocharger turbocharger). Preferably, it is done.
　可変ノズルが有するこのような機能を最大限に活用することにより、上述した通り、動力回収用排気タービンにおけるエネルギー回収を増大させ、ガスエンジンおよび動力回収用排気タービンによる出力の合計値を最大にすることが可能になる。 By making maximum use of such functions of the variable nozzle, as described above, the energy recovery in the power recovery exhaust turbine is increased, and the total output of the gas engine and the power recovery exhaust turbine is maximized. It becomes possible.
　本発明によれば、過給機の過給用タービンと動力回収用排気タービンとの双方において効率的にガスエンジンの排気エネルギーを回収することができる。 According to the present invention, the exhaust energy of the gas engine can be efficiently recovered in both the turbocharger turbocharger and the power recovery exhaust turbine.
　また、本発明によれば、ガスエンジンが発電機を駆動するようにして、システムによる主要出力が電力としてまとめられる。このことにより、エネルギー回収の制御を容易に行うことができ、利用しやすい形でエネルギーを得ることができる。また、排気の流路やストップ弁を適宜付加することにより、動力回収用排気タービンやその可変ノズルが故障等によって正常に機能しないときも、ガスエンジンを円滑に運転できるようになる。 Further, according to the present invention, the main output by the system is collected as electric power so that the gas engine drives the generator. As a result, energy recovery can be easily controlled, and energy can be easily obtained. Further, by appropriately adding an exhaust passage and a stop valve, the gas engine can be smoothly operated even when the exhaust turbine for power recovery and its variable nozzle do not function normally due to a failure or the like.
　さらに、本発明によれば、空燃比の許容幅の狭いガスエンジンを円滑に運転するとともに、動力回収用排気タービンにおけるエネルギー回収を含めて、排気のエネルギーを効率的に活用することができる。 Furthermore, according to the present invention, it is possible to smoothly operate a gas engine having a narrow allowable range of air-fuel ratio, and to efficiently use the energy of exhaust gas including energy recovery in an exhaust turbine for power recovery.
　特に、動力回収用排気タービンへ供給される排気の量がガスエンジンの全排気量の常に１０％以上となるように各タービンの可変ノズルの開度調整を行う場合、システム全体でみてさらに効率的なエネルギー活用を実現できる。この場合、設備コストの回収の面でも有利である。また、ガスエンジンの排気圧が給気圧と同等になるよう開度調整を行う場合、上記の利点は一層顕著になる。 In particular, when adjusting the opening of the variable nozzle of each turbine so that the amount of exhaust gas supplied to the exhaust turbine for power recovery is always 10% or more of the total exhaust amount of the gas engine, it is more efficient as a whole system. Energy utilization can be realized. In this case, it is advantageous also in terms of recovery of equipment costs. Further, when the opening degree is adjusted so that the exhaust pressure of the gas engine becomes equal to the supply air pressure, the above-described advantage becomes even more remarkable.
本発明の実施形態としてのガスエンジンシステムを示す系統図である。It is a systematic diagram showing a gas engine system as an embodiment of the present invention. 本発明の他の実施形態としてのガスエンジンシステムを示す系統図である。It is a systematic diagram which shows the gas engine system as other embodiment of this invention. 本発明の更なる他の実施形態としてのガスエンジンシステムを示す系統図である。It is a systematic diagram which shows the gas engine system as further another embodiment of this invention. 動力回収用排気タービンのＴ－Ｓ線図であって、絞り弁を使用する場合に発生する絞り損失を示す図である。It is a TS diagram of the exhaust turbine for power recovery, and shows the throttle loss that occurs when a throttle valve is used. 従来のガスエンジンシステムを示す系統図である。It is a systematic diagram which shows the conventional gas engine system. 従来の他のガスエンジンシステムを示す系統図である。It is a systematic diagram showing another conventional gas engine system. 従来の更なる他のガスエンジンシステムを示す系統図である。It is a systematic diagram showing another conventional gas engine system.
　以下、図１乃至図４を用いて、本発明のガスエンジンシステムおよびその制御方法について説明する。 Hereinafter, the gas engine system and the control method thereof according to the present invention will be described with reference to FIGS.
　図１～図３のそれぞれに、本発明の実施形態としてのガスエンジンシステムが示されている。いずれのものもターボコンパウンドシステム（ＴＣＳ）の一種を示しており、ガスエンジン１に、動力回収用の排気タービン２１が付設されている。 1 to 3 show a gas engine system as an embodiment of the present invention. Each of them shows a kind of turbo compound system (TCS), and an exhaust turbine 21 for power recovery is attached to the gas engine 1.
　ガスエンジン１の出力軸に、発電機８が連結されている。また、ガスエンジン１に、排気流路２と給気流路５を介して過給機１０が接続されるとともに、ガスエンジン１に燃料ガスとしてＬＮＧを送る燃料供給管７が接続されている。過給機１０は、一軸上に設けられた過給用タービン１１とブロア１２とを有しており、排気流路２から供給されるガスエンジン１の排気のエネルギーによって過給用タービン１１を回転させ、その動力でブロア１２を駆動して、給気流路５を通してガスエンジン１に給気を過給する。給気流路５には、給気を冷却するための空気冷却器６が設けられている。 The generator 8 is connected to the output shaft of the gas engine 1. A supercharger 10 is connected to the gas engine 1 through an exhaust passage 2 and an air supply passage 5, and a fuel supply pipe 7 that sends LNG as fuel gas to the gas engine 1 is connected. The supercharger 10 has a turbocharger turbine 11 and a blower 12 provided on one axis, and rotates the turbocharger 11 by the energy of the exhaust gas from the gas engine 1 supplied from the exhaust passage 2. Then, the blower 12 is driven with the motive power, and the gas engine 1 is supercharged through the air supply passage 5. The air supply channel 5 is provided with an air cooler 6 for cooling the supply air.
　ガスエンジン１の排気流路２から分岐する形で排気の第１分岐流路３が接続され、その先に上記の動力回収用排気タービン２１が設けられている。すなわち、図１～図３のガスエンジンシステムでは、ガスエンジン１からの排気を排気流路２に送って過給機１０を駆動するとともに、この排気流路２から分岐した第１分岐流路３にガスエンジン１からの排気を分流させて、動力回収用排気タービン２１を駆動する。 The first branch flow path 3 for exhaust gas is connected so as to branch from the exhaust flow path 2 of the gas engine 1, and the power recovery exhaust turbine 21 is provided at the end thereof. That is, in the gas engine system of FIGS. 1 to 3, the exhaust from the gas engine 1 is sent to the exhaust passage 2 to drive the supercharger 10 and the first branch passage 3 branched from the exhaust passage 2. Then, the exhaust gas from the gas engine 1 is diverted to drive the exhaust turbine 21 for power recovery.
　図１のガスエンジンシステムでは、動力回収用排気タービン２１に発電機２２が接続され、分流された排気から電力としてエネルギーを回収することとしている。また、図２のシステムでは、動力回収用排気タービン２１の出力軸が、減速機２３を介してガスエンジン１の出力軸に連結されており、分流された排気のエネルギーの一部をガスエンジン１に還元するようにしている。 In the gas engine system of FIG. 1, a generator 22 is connected to the exhaust turbine 21 for power recovery, and energy is recovered from the shunted exhaust as electric power. In the system of FIG. 2, the output shaft of the power recovery exhaust turbine 21 is connected to the output shaft of the gas engine 1 via the speed reducer 23, and a part of the energy of the divided exhaust gas is transferred to the gas engine 1. I'm trying to reduce it.
　こうした図１および図２のガスエンジンシステムでは、排気のエネルギーをできるだけ多く回収してエネルギー利用率を高めるよう、次のような工夫を施している。
　a)　過給機１０の過給用タービン１１と動力回収用排気タービン２１とのそれぞれに、ノズル面積の変更が可能な可変ノズル式のものを採用した。これにより、タービンの上流側で、絞り損失が生じる絞り弁を使用する必要がなく、各タービン１１、２１で回収されるエネルギーを増大させることができる（図４参照）。 In the gas engine system shown in FIGS. 1 and 2, the following measures are taken to recover as much exhaust energy as possible to increase the energy utilization rate.
a) A variable nozzle type capable of changing the nozzle area was adopted for each of the turbocharging turbine 11 and the power recovery exhaust turbine 21 of the supercharger 10. Thereby, it is not necessary to use a throttle valve that causes a throttle loss on the upstream side of the turbine, and the energy recovered by each turbine 11, 21 can be increased (see FIG. 4).
　b)　過給機１０の過給用タービン１１の可変ノズル１１ａを操作してそのノズル面積を適切にすることにより、
　・　燃料量に応じた適切な量の給気を過給機１０がガスエンジン１に過給するようにして、ガスエンジン１の運転に適した所定の空燃比を実現し、また、
　・　第１分岐流路３から動力回収用排気タービン２１へ至る排気の量を増減させて、ガスエンジン１と動力回収用排気タービン２１との合計の出力が最大になるように制御するものとする。なお、過給用タービン１１の可変ノズル１１ａを絞るとガスエンジン１の排気圧が高くなってガスエンジン１の出力が低下することがあるが、動力回収用排気タービン２１の出力との合計値が増大するため、問題としない。 b) By operating the variable nozzle 11a of the supercharging turbine 11 of the supercharger 10 to make the nozzle area appropriate,
A supercharger 10 supercharges the gas engine 1 with an appropriate amount of air supply according to the amount of fuel to achieve a predetermined air-fuel ratio suitable for the operation of the gas engine 1;
The amount of exhaust from the first branch flow path 3 to the power recovery exhaust turbine 21 is increased or decreased to control the total output of the gas engine 1 and the power recovery exhaust turbine 21 to the maximum. . If the variable nozzle 11a of the supercharging turbine 11 is throttled, the exhaust pressure of the gas engine 1 may increase and the output of the gas engine 1 may decrease. However, the total value with the output of the power recovery exhaust turbine 21 is Because it increases, it is not a problem.
　c)　上記b)の制御を行うため、動力回収用排気タービン２１の可変ノズル２１ａは、第１分岐流路３に送られる排気による出力を最大化するように開度調整を行う。絞り弁には備わっていない可変ノズル２１ａのこのような機能を最大限に活用するためである。 C) In order to perform the control of b) above, the variable nozzle 21a of the power recovery exhaust turbine 21 adjusts the opening so as to maximize the output by the exhaust gas sent to the first branch flow path 3. This is to make maximum use of such a function of the variable nozzle 21a not provided in the throttle valve.
　d)　やはり上記b)の制御を実現するため、動力回収用排気タービン２１へ供給される排気の量が、夏季においてもガスエンジン１の全排気量の１０％以上（冬季には２０％程度以上）となるよう、上記各可変ノズル１１ａ、２１ａの開度を調整する。このようにすると、動力回収用排気タービン２１におけるエネルギー回収を積極化して、ガスエンジン１と動力回収用排気タービン２１との合計出力を容易に増大させることができる。 d) To achieve the control of b) above, the amount of exhaust gas supplied to the power recovery exhaust turbine 21 is 10% or more of the total displacement of the gas engine 1 even in summer (about 20% or more in winter). ), The opening degree of each of the variable nozzles 11a and 21a is adjusted. If it does in this way, energy recovery in the exhaust turbine 21 for power recovery can be made active, and the total output of the gas engine 1 and the exhaust turbine 21 for power recovery can be increased easily.
　e)　上記d)のようにするため、場合によっては、過給機１０の過給用タービン１１の可変ノズル１１ａの開度を、ガスエンジン１の排気圧力が給気圧力と同等（給気圧力と同一か、それよりやや低い程度）になるまで絞る。過給用タービン１１の可変ノズル１１ａをこのように絞ると、動力回収用排気タービン２１へ供給される排気の量を上記d)の程度以上に増やし、システムの合計出力をより一層増大させることができる。 e) In order to perform the above d), in some cases, the opening degree of the variable nozzle 11a of the turbocharger 11 of the supercharger 10 is set so that the exhaust pressure of the gas engine 1 is equal to the supply pressure (supply pressure). Until it is equal to or slightly lower than If the variable nozzle 11a of the turbocharging turbine 11 is throttled in this way, the amount of exhaust gas supplied to the power recovery exhaust turbine 21 can be increased to more than the level of d), and the total output of the system can be further increased. it can.
　図３のガスエンジンシステムは、図２のシステムを基本にするものだが、実用性を高めるためにつぎの構成が付加されている。すなわち、動力回収用排気タービン２１に至る排気の第１分岐流路３に第１ストップ弁Ｖ１が設けられるとともに、過給機１０の過給用タービン１１へ至る排気流路２に、大気に通じる別の第２分岐流路４が接続され、この第２分岐流路４に第２ストップ弁Ｖ２が設けられている。 The gas engine system of FIG. 3 is based on the system of FIG. 2, but the following configuration is added to enhance practicality. That is, the first stop valve V1 is provided in the first branch flow path 3 of the exhaust gas that reaches the power recovery exhaust turbine 21, and the exhaust gas flow path 2 that leads to the supercharge turbine 11 of the supercharger 10 leads to the atmosphere. Another second branch flow path 4 is connected, and the second branch flow path 4 is provided with a second stop valve V2.
　このシステムでは、動力回収用排気タービン２１またはその可変ノズル２１ａが故障等した場合の対応を有利に行うことができる。すなわち、まず故障等のない通常運転時には、第１分岐流路３の第１ストップ弁Ｖ１を全開にし、第２分岐流路４の第２ストップ弁Ｖ２を全閉にして、実質上図２と同じ系統にしてシステムを運転する。その一方、動力回収用排気タービン２１等に故障が発生した場合には、第１ストップ弁Ｖ１を全閉にして動力回収用排気タービン２１への排気供給を止める（さらに減速機２３と動力回収用排気タービン２１との接続を解く）とともに、第２ストップ弁Ｖ２の開度を調整して、過給機１０に使用しない余剰の排気を第２分岐流路４から大気中に放出する。動力回収用排気タービン２１を使用しない間、エネルギー回収効率が低下するのはやむを得ないが、ガスエンジン１の円滑な運転を継続しながら、動力回収用排気タービン２１等の修理を進めることができる。 This system can advantageously cope with a case where the exhaust turbine 21 for power recovery or its variable nozzle 21a breaks down. That is, first, during normal operation without failure, the first stop valve V1 of the first branch flow path 3 is fully opened and the second stop valve V2 of the second branch flow path 4 is fully closed. Operate the system in the same system. On the other hand, if a failure occurs in the power recovery exhaust turbine 21 or the like, the first stop valve V1 is fully closed to stop the supply of exhaust gas to the power recovery exhaust turbine 21 (further, the speed reducer 23 and the power recovery At the same time, the degree of opening of the second stop valve V2 is adjusted, and surplus exhaust not used in the supercharger 10 is discharged from the second branch flow path 4 into the atmosphere. While the power recovery exhaust turbine 21 is not used, the energy recovery efficiency is inevitably lowered, but repair of the power recovery exhaust turbine 21 and the like can proceed while the gas engine 1 continues to operate smoothly.
　なお、図３のシステムにおいて、動力回収用排気タービン２１の出力軸が、図１の例のように発電機に接続されてもよい。その場合も、可変ノズル２１ａが故障等した場合の対応をやはり有利に行うことができる。 In the system of FIG. 3, the output shaft of the power recovery exhaust turbine 21 may be connected to a generator as in the example of FIG. In such a case as well, it is possible to advantageously cope with the case where the variable nozzle 21a breaks down.
　１　ガスエンジン
　２　排気流路
　３　第１分岐流路
　５　給気流路
　８　発電機
　１０　過給機
　１１　過給用タービン
　１１ａ　可変ノズル
　１２　ブロア
　２１　動力回収用排気タービン
　２１ａ　可変ノズル
　２２　発電機 DESCRIPTION OF SYMBOLS 1 Gas engine 2 Exhaust flow path 3 1st branch flow path 5 Supply air flow path 8 Generator 10 Supercharger 11 Supercharging turbine 11a Variable nozzle 12 Blower 21 Exhaust turbine for power recovery 21a Variable nozzle 22 Generator

Claims (11)

  1. 　ガスエンジンと、
    　前記ガスエンジンからの排気が供給されて駆動される過給用タービンを有し、当該過給用タービンが駆動されることにより前記ガスエンジンに給気を過給する過給機と、
    　前記ガスエンジンに接続され、当該ガスエンジンから前記過給用タービンに供給される排気の一部が供給されて駆動される動力回収用排気タービンと、を備え、
    　前記過給用タービンおよび前記動力回収用排気タービンは、開度調整可能な可変ノズルをそれぞれ有していることを特徴とするガスエンジンシステム。     A gas engine,
    A turbocharger that is driven by being supplied with exhaust gas from the gas engine, and that supercharges the gas engine by driving the turbocharger;
    A power recovery exhaust turbine connected to the gas engine and driven by a part of the exhaust gas supplied from the gas engine to the supercharging turbine;
    The supercharging turbine and the power recovery exhaust turbine each have a variable nozzle whose opening degree can be adjusted.
  2. 　前記ガスエンジンに発電機が接続され、
    　前記動力回収用排気タービンに、前記発電機とは異なる他の発電機、または前記ガスエンジンが接続されていることを特徴とする請求項１に記載のガスエンジンシステム。     A generator is connected to the gas engine;
    The gas engine system according to claim 1, wherein another generator different from the generator or the gas engine is connected to the power recovery exhaust turbine.
  3. 　前記ガスエンジンと前記過給用タービンとの間に、当該ガスエンジンから当該過給用タービンに排気を供給する排気流路が接続され、
    　前記排気流路に、前記動力回収用排気タービンに接続された第１分岐流路が接続されるとともに、当該排気流路を流れる排気を大気に放出可能な第２分岐流路が接続されており、
    　前記第１分岐流路に、当該第１分岐流路を開閉可能な第１ストップ弁が設けられ、
    　前記第２分岐流路に、当該第２分岐流路を開閉可能な第２ストップ弁が設けられていることを特徴とする請求項１または２に記載のガスエンジンシステム。     An exhaust passage for supplying exhaust gas from the gas engine to the supercharging turbine is connected between the gas engine and the supercharging turbine.
    A first branch passage connected to the exhaust turbine for power recovery is connected to the exhaust passage, and a second branch passage capable of releasing the exhaust gas flowing through the exhaust passage to the atmosphere is connected to the exhaust passage. ,
    The first branch flow path is provided with a first stop valve capable of opening and closing the first branch flow path,
    The gas engine system according to claim 1 or 2, wherein a second stop valve capable of opening and closing the second branch flow path is provided in the second branch flow path.
  4. 　前記過給用タービンおよび前記動力回収用排気タービンの前記可変ノズルの開度は、前記ガスエンジンにおいて所定の空燃比が実現するとともに、当該ガスエンジンおよび前記動力回収用排気タービンによる出力の合計値が増大するように調整されることを特徴とする請求項１乃至３のいずれかに記載のガスエンジンシステム。 The opening degree of the variable nozzles of the supercharging turbine and the power recovery exhaust turbine is such that a predetermined air-fuel ratio is realized in the gas engine, and the total output of the gas engine and the power recovery exhaust turbine is The gas engine system according to claim 1, wherein the gas engine system is adjusted so as to increase.
  5. 　前記過給用タービンおよび前記動力回収用排気タービンの前記可変ノズルの開度は、当該動力回収用排気タービンに供給される排気の量が、外気温にかかわらず常に前記ガスエンジンの全排気量の１０％以上となるように調整されることを特徴とする請求項４に記載のガスエンジンシステム。 The degree of opening of the variable nozzles of the supercharging turbine and the power recovery exhaust turbine is such that the amount of exhaust supplied to the power recovery exhaust turbine is always equal to the total displacement of the gas engine regardless of the outside temperature. It adjusts so that it may become 10% or more, The gas engine system of Claim 4 characterized by the above-mentioned.
  6. 　前記過給用タービンの前記可変ノズルの開度は、前記ガスエンジンから排出される排気の圧力が当該ガスエンジンに過給される給気の圧力と同等になるように調整されることを特徴とする請求項５に記載のガスエンジンシステム。 The opening degree of the variable nozzle of the supercharging turbine is adjusted so that the pressure of the exhaust gas discharged from the gas engine is equal to the pressure of the air supply charged to the gas engine. The gas engine system according to claim 5.
  7. 　前記動力回収用排気タービンの前記可変ノズルの開度は、当該動力回収用排気タービンの出力を最大化するように調整されることを特徴とする請求項４乃至６のいずれかに記載のガスエンジンシステム。 The gas engine according to any one of claims 4 to 6, wherein the opening degree of the variable nozzle of the exhaust turbine for power recovery is adjusted so as to maximize the output of the exhaust turbine for power recovery. system.
  8. 　請求項１乃至３のいずれかに記載のガスエンジンシステムの制御方法において、
    　前記過給用タービンおよび前記動力回収用排気タービンの前記可変ノズルの開度は、前記ガスエンジンにおいて所定の空燃比が実現するとともに、当該ガスエンジンおよび前記動力回収用排気タービンによる出力の合計値が増大するように調整されることを特徴とするガスエンジンシステムの制御方法。     In the control method of the gas engine system according to any one of claims 1 to 3,
    The opening degree of the variable nozzles of the supercharging turbine and the power recovery exhaust turbine is such that a predetermined air-fuel ratio is realized in the gas engine, and the total output of the gas engine and the power recovery exhaust turbine is A control method of a gas engine system, characterized by being adjusted to increase.
  9. 　前記過給用タービンおよび前記動力回収用排気タービンの前記可変ノズルの開度は、当該動力回収用排気タービンに供給される排気の量が、外気温にかかわらず常に前記ガスエンジンの全排気量の１０％以上となるように調整されることを特徴とする請求項８に記載のガスエンジンシステムの制御方法。 The degree of opening of the variable nozzles of the supercharging turbine and the power recovery exhaust turbine is such that the amount of exhaust supplied to the power recovery exhaust turbine is always equal to the total displacement of the gas engine regardless of the outside temperature. The gas engine system control method according to claim 8, wherein the gas engine system is adjusted to be 10% or more.
  10. 　前記過給用タービンの前記可変ノズルの開度は、前記ガスエンジンから排出される排気の圧力が当該ガスエンジンに過給される給気の圧力と同等になるように調整されることを特徴とする請求項９に記載のガスエンジンシステムの制御方法。 The opening degree of the variable nozzle of the supercharging turbine is adjusted so that the pressure of the exhaust gas discharged from the gas engine is equal to the pressure of the air supply charged to the gas engine. The method for controlling a gas engine system according to claim 9.
  11. 　前記動力回収用排気タービンの前記可変ノズルの開度は、当該動力回収用排気タービンの出力を最大化するように調整されることを特徴とする請求項８乃至１０のいずれかに記載のガスエンジンシステムの制御方法。 The gas engine according to any one of claims 8 to 10, wherein the opening degree of the variable nozzle of the power recovery exhaust turbine is adjusted so as to maximize the output of the power recovery exhaust turbine. How to control the system.
PCT/JP2010/051863 2009-02-10 2010-02-09 Gas engine system and method for controlling same WO2010092945A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2009028650 2009-02-10
JP2009-028650 2009-02-10

Publications (1)

Publication Number Publication Date
WO2010092945A1 true WO2010092945A1 (en) 2010-08-19

Family

ID=42561787

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2010/051863 WO2010092945A1 (en) 2009-02-10 2010-02-09 Gas engine system and method for controlling same

Country Status (1)

Country Link
WO (1) WO2010092945A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102010028200A1 (en) * 2010-04-26 2012-06-28 Man Diesel & Turbo Se Internal combustion engine arrangement of power plant, has exhaust gas turbine equipped with turbine inlet connected to exhaust branch line, so that exhaust gas branched off from exhaust outlet pipe is supplied to exhaust gas turbine
JP2013100794A (en) * 2011-11-09 2013-05-23 Ygk:Kk Cogeneration system
WO2014129562A1 (en) * 2013-02-21 2014-08-28 三菱重工業株式会社 Tank internal pressure suppression device
WO2014170559A1 (en) * 2013-04-15 2014-10-23 Valeo Systemes De Controle Moteur Method for improving the energy efficiency of a drive system
EP2868891A1 (en) * 2013-08-28 2015-05-06 Deere & Company A power system including a variable geometry turbocompound turbine
EP2904257A1 (en) * 2012-10-02 2015-08-12 Caterpillar Energy Solutions GmbH Gas reformation with motor driven compressor
AT515936B1 (en) * 2014-06-02 2016-01-15 Avl List Gmbh Internal combustion engine
US9267442B2 (en) 2012-03-01 2016-02-23 Cummins Limited Turbo-compound turbocharged engine and method of operating turbo-compound turbocharged engine

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6282214A (en) * 1985-10-02 1987-04-15 Kawasaki Heavy Ind Ltd Compound engine
JP2000045817A (en) * 1998-07-31 2000-02-15 Hino Motors Ltd Hybrid automobile
JP2005320938A (en) * 2004-05-11 2005-11-17 Yanmar Co Ltd Exhaust heat recovery device and exhaust heat recovery method
WO2007082398A1 (en) * 2006-01-23 2007-07-26 Abb Turbo Systems Ag Adjustable guiding device
WO2008025749A1 (en) * 2006-08-28 2008-03-06 Abb Turbo Systems Ag Sealing means of adjustable guide vanes

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6282214A (en) * 1985-10-02 1987-04-15 Kawasaki Heavy Ind Ltd Compound engine
JP2000045817A (en) * 1998-07-31 2000-02-15 Hino Motors Ltd Hybrid automobile
JP2005320938A (en) * 2004-05-11 2005-11-17 Yanmar Co Ltd Exhaust heat recovery device and exhaust heat recovery method
WO2007082398A1 (en) * 2006-01-23 2007-07-26 Abb Turbo Systems Ag Adjustable guiding device
WO2008025749A1 (en) * 2006-08-28 2008-03-06 Abb Turbo Systems Ag Sealing means of adjustable guide vanes

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102010028200A1 (en) * 2010-04-26 2012-06-28 Man Diesel & Turbo Se Internal combustion engine arrangement of power plant, has exhaust gas turbine equipped with turbine inlet connected to exhaust branch line, so that exhaust gas branched off from exhaust outlet pipe is supplied to exhaust gas turbine
DE102010028200B4 (en) * 2010-04-26 2016-02-04 Man Diesel & Turbo Se Engine assembly
JP2013100794A (en) * 2011-11-09 2013-05-23 Ygk:Kk Cogeneration system
US9267442B2 (en) 2012-03-01 2016-02-23 Cummins Limited Turbo-compound turbocharged engine and method of operating turbo-compound turbocharged engine
EP2904257A1 (en) * 2012-10-02 2015-08-12 Caterpillar Energy Solutions GmbH Gas reformation with motor driven compressor
JP2014163400A (en) * 2013-02-21 2014-09-08 Mitsubishi Heavy Ind Ltd Tank internal pressure restraining device
CN104870885A (en) * 2013-02-21 2015-08-26 三菱重工业株式会社 Tank internal pressure suppression device
WO2014129562A1 (en) * 2013-02-21 2014-08-28 三菱重工業株式会社 Tank internal pressure suppression device
WO2014170559A1 (en) * 2013-04-15 2014-10-23 Valeo Systemes De Controle Moteur Method for improving the energy efficiency of a drive system
CN105324563A (en) * 2013-04-15 2016-02-10 法雷奥电机控制系统公司 Method for improving the energy efficiency of a drive system
EP2868891A1 (en) * 2013-08-28 2015-05-06 Deere & Company A power system including a variable geometry turbocompound turbine
US9534534B2 (en) 2013-08-28 2017-01-03 Deere & Company Power system including a variable geometry turbocompound turbine
AT515936B1 (en) * 2014-06-02 2016-01-15 Avl List Gmbh Internal combustion engine
AT515936A4 (en) * 2014-06-02 2016-01-15 Avl List Gmbh Internal combustion engine

Similar Documents

Publication Publication Date Title
WO2010092945A1 (en) Gas engine system and method for controlling same
US8794000B2 (en) Natural gas compression system
US9915195B2 (en) Forced induction device for a combustion engine, combustion engine and method for operating a combustion engine
US8429912B2 (en) Dual turbocharged internal combustion engine system with compressor and turbine bypasses
US6901759B2 (en) Method for operating a partially closed, turbocharged gas turbine cycle, and gas turbine system for carrying out the method
JP2006506576A (en) Sequential turbocharger and sequential turbocharger method for internal combustion engine
CN102425488A (en) Adjustable two-stage supercharging sequential system applied to V-shaped diesel engine
JP2009115089A (en) Engine with supercharger and its operating method
JP3674254B2 (en) EGR device for supercharged engine
US8109093B2 (en) Method and an arrangement in connection with a turbocharged piston engine
JPS5982526A (en) Supercharger for internal-combustion engine
KR101692173B1 (en) Exhaust heat recovery system and exhaust heat recovery method
CN111794854A (en) Method and device for operating an internal combustion engine having a supercharging system
JP2009191668A (en) Supercharging device and supercharging engine system
JP2012197716A (en) Exhaust loss recovery device
EP2726726B1 (en) An internal combustion engine and method of operating an internal combustion engine
JP2007024010A (en) Combustion assisting turbo supercharging device
JP2009191667A (en) Supercharging device and supercharging engine system
US20150345378A1 (en) Method for the Operation of an Internal Combustion Engine
JPH10169455A (en) Turbo charger engine
KR102463199B1 (en) Engine system
JP2007077899A (en) Two-stage supercharging system
JP5461226B2 (en) Two-stage turbocharging system
CN106870176B (en) Method for operating a drive system for a motor vehicle and corresponding drive system
JP2001342839A (en) Turbo supercharging system

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10741222

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10741222

Country of ref document: EP

Kind code of ref document: A1