Search

JP-2026075346-A - Engine system and method of operating the engine system

JP2026075346AJP 2026075346 AJP2026075346 AJP 2026075346AJP-2026075346-A

Abstract

[Problem] In controlling an engine that performs both ammonia and non-ammonia operation, the goal is to remove unburned ammonia and nitrogen oxides (NO, NO₂ , N₂O ) from the exhaust gas using a catalyst during ammonia operation, thereby reducing the long-term degradation of the catalyst due to exhaust gas during diesel operation. [Solution] The exhaust path 30 of the engine 2, which performs ammonia operation and diesel operation, is provided with a first exhaust path 81 equipped with a catalytic converter 60 and a second exhaust path 82 that bypasses the catalytic converter. First and second switching devices 71 and 72 are provided in both of these exhaust paths 81 and 82, respectively. The engine starts in diesel operation with the exhaust path set to the second exhaust path. Before switching to ammonia operation, the exhaust path is set to the first exhaust path to heat the catalytic converter 60, and when it reaches the activation temperature, it switches to ammonia operation. [Selection Diagram] Figure 1

Inventors

  • 齊藤 奈津美
  • 増田 裕
  • 高橋 秀幸
  • 成勢 弘城
  • 中川 貴裕
  • 大場 啓道

Assignees

  • 株式会社ＩＨＩ原動機
  • 株式会社ジャパンエンジンコーポレーション

Dates

Publication Date
20260508
Application Date
20241022

Claims (8)

  1. An engine that switches between ammonia operation, which uses ammonia as fuel, and non-ammonia operation, which does not use ammonia as fuel, A first exhaust path connected to the engine and equipped with a catalyst for processing ammonia combustion gases, and a second exhaust path not equipped with the catalyst, A switching device for switching between the first exhaust path and the second exhaust path, A control device that controls the engine and the switching device, An engine system having, The control device is capable of selecting between an ammonia mode, which is an operating state in which the first exhaust path is used in ammonia operation, and a non-ammonia mode, which is an operating state in which the second exhaust path is used in non-ammonia operation. Furthermore, an engine system that controls the system to enter a catalyst warm-up mode, which is an operating state using the first exhaust path in non-ammonia operation, before transitioning to the ammonia mode.
  2. The engine system according to claim 1, wherein the control device controls the supply of ammonia to the catalyst during the catalyst warm-up mode.
  3. The engine system according to claim 1 or 2, wherein the control device performs control to switch to the ammonia mode after the temperature of the catalyst reaches a temperature at which it can process the exhaust gas from the ammonia operation, through operation in the catalyst warm-up mode.
  4. The engine system according to claim 3, wherein the control device controls the supply of ammonia to the catalyst in the ammonia mode.
  5. The engine system according to claim 1 or 2, wherein the control device, in the ammonia mode or the catalyst warm-up mode, performs control to transition to a catalyst warm-up mode, which is an operating state using the second exhaust path in non-ammonia operation, while maintaining the function of supplying ammonia to the engine, if the exhaust temperature of the engine falls below the temperature at which the activity of the catalyst can be maintained.
  6. The engine system according to claim 5, wherein the control device controls the cessation of ammonia supply to the catalyst in the catalyst heating mode.
  7. The engine system according to claim 1 or 2, wherein the control device controls the start of the engine operation in the non-ammonia mode.
  8. An engine that switches between ammonia operation, which uses ammonia as fuel, and non-ammonia operation, which does not use ammonia as fuel, A first exhaust path connected to the engine and equipped with a catalyst for processing ammonia combustion gases, and a second exhaust path not equipped with the catalyst, A switching device for switching between the first exhaust path and the second exhaust path, A method for operating an engine system having, In the ammonia operation, the first exhaust path is used, and in the non-ammonia operation, the second exhaust path is used. An engine system operating method comprising, before transitioning to the operating state using the first exhaust path in ammonia operation, operating the system in the operating state using the first exhaust path in non-ammonia operation.

Description

This invention relates to an engine system equipped with an engine capable of selectively performing ammonia operation using ammonia-containing fuel and non-ammonia operation using fuels other than ammonia, and to a method for operating such an engine system. Patent Document 1 below discloses an invention of a reciprocating engine system. This reciprocating engine system comprises a reciprocating engine and a control device for controlling it. The reciprocating engine includes a cylinder forming a combustion chamber, a piston that reciprocates within the cylinder, an ammonia fuel supply device that supplies gaseous ammonia to the cylinder for premixing with air, and a liquid auxiliary fuel supply device that supplies liquid auxiliary fuel to the cylinder for ignition of the ammonia. The control device controls the reciprocating engine so that it can perform co-firing operation with ammonia and liquid auxiliary fuel while the compression end temperature in the cylinder is above a predetermined temperature that prevents delayed combustion of ammonia. According to this reciprocating engine system, the proportion of ammonia in the mixture of ammonia and liquid auxiliary fuel can be increased compared to conventional systems, thereby significantly reducing carbon dioxide emissions in a reciprocating engine using ammonia as fuel. International Publication Number WO2023/090218 This is a diagram illustrating the configuration of an engine system according to one embodiment.This is an explanatory diagram of the diesel mode in one embodiment of the engine system.This is an explanatory diagram of the ammonia mode in an engine system of one embodiment.This is an explanatory diagram showing the transitions between multiple operating modes in one embodiment of an engine system.This is a table/diagram showing the characteristics of multiple operating modes in an engine system of one embodiment, item by item.This graph shows the temperature changes at the inlet and outlet of the catalyst provided in the first exhaust path during the catalyst warm-up mode of an engine system according to one embodiment.This graph shows the effect obtained by injecting ammonia into the catalyst of the first exhaust path during the catalyst warm-up mode of an engine system according to one embodiment, as shown by the reduction in the concentration of nitrogen oxides at the outlet of the catalyst provided in the first exhaust path. Embodiments of the present invention will be described with reference to Figures 1 to 7. Figure 1 is a diagram showing the configuration of an engine system 1 according to one embodiment. As shown in Figure 1, the engine system 1 includes an engine 2 and a control device 3 that controls the engine system 1. The application of the engine 2 shown in Figure 1 is not particularly limited; for example, it may be a marine engine that directly or indirectly drives a propeller, or a power generation engine that drives a generator. As will be explained in more detail later, engine 2 is an engine that can selectively perform ammonia operation, which uses a fuel containing ammonia ( NH3 ), and diesel operation, which uses a fuel other than ammonia. In addition, the control device 3 has multiple control modes (operating modes), as will be explained later, as its control modes include an ammonia mode for causing engine 2 to perform ammonia operation and a diesel mode for causing engine 2 to perform diesel operation. Engine 2 comprises a cylinder 11 forming a combustion chamber 10, a piston 12 reciprocating within the cylinder 11, a crankshaft 13 connected to the piston 12, a rotation detection sensor 14 for detecting the rotation of the crankshaft 13, and a torque detection sensor 15 for detecting the torque of the crankshaft 13. The torque detection sensor 15 may be omitted depending on the specifications of the engine 2; in that case, a torque or load value calculated by the control device 3 is used. The crankshaft 13 is connected to a driven device driven by the engine 2. For example, if the engine 2 is a marine main engine, it is connected to the propeller shaft of the ship; if it is a ship's power generator or a land-based power generator, it is connected to the generator shaft. The cylinder head of cylinder 11 is connected to an intake passage 20 and an exhaust passage 30. The cylinder head is also equipped with an intake valve 21 for opening and closing the intake passage 20, and an exhaust valve 31 for opening and closing the exhaust passage 30. Furthermore, the cylinder head is equipped with a liquid fuel injection valve 53 for injecting liquid auxiliary fuel into the combustion chamber 10, and an ignition device 55. The ignition device 55 is, for example, a micro-pilot oil injection valve and is used in ammonia mode, but can be omitted if micro-pilot injection is possible with the liquid combustion injection valve 53. The intake path 20 includes a compressor 22 for compressing combustion air, an air heating device 24 i