JP2501562Y2 - Intake cooling structure of LNG engine - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an intake cooling structure of an LNG engine,
LNG can be cooled by using the latent heat of vaporization of NG to cool the intake air
The present invention relates to an intake air cooling structure for an LNG engine that can reduce the size and weight of a vaporizer that vaporizes air and reduce costs.

[Conventional technology]

Gasoline, light oil, etc. are mainly used as the fuel for the engine, which is an internal combustion engine, but in view of various problems such as pollution by harmful exhaust substances and depletion of resources, as an approximate or alternative fuel.
LNG (liquefied natural gas) is drawing attention. In this LNG engine that uses LNG as fuel, LNG in the fuel tank is supplied by the fuel supply pipe. LNG supplied by the fuel supply pipe is
It is vaporized by the vaporizer and regulated by the regulator.

An example of a vaporizer for vaporizing the LNG is shown in FIG. In the figure, 102 is an LNG engine, 104 is an air cleaner, 106 is an intake pipe, 108 is a fuel supply pipe, 110 is a vaporizer, 112 is a mixer, and 114 is a gas meter. A vaporizer 110 that vaporizes LNG is provided in the middle of an intake pipe 106 that connects the LNG engine 102 and the air cleaner 104. This vaporizer 110 is an intake pipe 1
A case 120 having a heat exchange passage 118 communicating with the intake passage 116 of 06, and a heat transfer tube provided in the middle of the fuel supply pipe 108 and arranged in the heat exchange passage 118 of the case 120.
122 and heat transfer fins 124 provided on the heat transfer tube 122.

As a result, the LNG and the intake air are heat-exchanged by the heat transfer tubes and the heat transfer fins in the heat exchange passage of the vaporizer, and the LNG
Is vaporized and supplied to the LNG engine, and the latent heat of vaporization of this LNG is used to cool the intake air to improve output, prevent knocking, and reduce NOx.

Thus, an LNG engine that cools intake air by utilizing latent heat of vaporization of LNG is disclosed in JP-A-1-195963. The one disclosed in this publication can cool intake air without causing clogging of the fuel supply pipe due to frost formation,
This is to improve the output.

[Problems to be solved by the invention]

However, the conventional vaporizer that vaporizes LNG is
There is a problem that the capacity and weight are large and large, and the cost is high. For this reason, when the LNG engine is installed as a prime mover in a vehicle or the like, the layout in the engine room becomes difficult and the cost increases, which is an obstacle to the practical use of the LNG engine vehicle. Was there.

[Purpose of device]

Therefore, the purpose of this invention is to cool the intake air by utilizing the latent heat of vaporization of LNG, and to reduce the size and weight of the vaporizer that vaporizes LNG and to reduce the cost. To realize an intake air cooling structure for an LNG engine that can avoid the inconvenience that the layout in the engine room becomes difficult when mounted as a prime mover and the inconvenience that causes an increase in cost, and can eliminate obstacles to the practical use of LNG engine vehicles. It is in.

[Means for solving problems]

In order to achieve this object, the present invention relates to an intake cooling structure for an LNG engine that cools intake air by utilizing latent heat of vaporization of LNG vaporized by a vaporizer, and the vaporizer is provided in the air cleaner of the LNG engine. An oxygen enrichment device having an oxygen enrichment film that selectively permeates oxygen is provided in an intake passage communicating with the combustion chamber of the LNG engine, and the oxygen enrichment device is provided in the intake passage downstream of the oxygen enrichment device. Oxygen having an increased oxygen concentration on the downstream side of the oxygen-enriched film by causing a pressure difference between the upstream side and the downstream side of the oxygen-enriched film to produce a pressure difference between the upstream side and the downstream side of the oxygen-enriched film. A suction pump for generating enriched air is provided, an exhaust fan for discharging the nitrogen-enriched air produced is provided on the upstream side of the oxygen-enriched film, and a downstream side of the exhaust fan is provided so as to be directed to the suction pump. Octopus The features.

[Action]

According to the configuration of this invention, by providing the vaporizer for vaporizing LNG in the air cleaner of the LNG engine, heat and heat can be exchanged between the LNG and the intake air in the air cleaner and the volume and weight of the vaporizer can be shared by sharing the air cleaner case. It is possible to reduce the number of components and eliminate the need for components.

Further, the downstream side of the exhaust fan that discharges the nitrogen-enriched air generated on the upstream side of the oxygen enrichment membrane of the oxygen concentrator is provided so as to be directed to the suction pump that creates a pressure difference in the oxygen enrichment membrane. Thereby, the suction pump can be cooled.

〔Example〕

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

1 and 2 show an embodiment of the present invention.
In the figure, reference numeral 2 denotes an LNG engine. In this LNG engine 2, an air cleaner 4 and a combustion chamber 6 are connected by an intake pipe 8. The intake pipe 8 forms an intake passage 10.
An oxygen enrichment device 12 is provided in the middle of the intake pipe 8. The oxygen enrichment device 12 is provided with an oxygen enrichment film 16 made of a gas-selective permeable film or the like that selectively permeates oxygen as a specific gas in the main body 14. A suction pump 18 is provided downstream of the intake passage 10 of the main body 14. This suction pump 18
Generates a pressure difference between the upstream side and the downstream side of the intake passage 10 of the oxygen enriched film 16, and produces oxygen-enriched air with an increased oxygen concentration on the downstream side of the intake passage 10 of the oxygen enriched film 16.

In addition, the intake passage of the oxygen enriched film 16 is reduced by reducing the oxygen concentration.
An exhaust fan 20 is provided in the main body 12 in order to discharge the nitrogen-enriched air having a high nitrogen concentration generated on the upstream side. The downstream side of the exhaust fan 20 is the suction pump.
I am oriented to 18. This makes it possible to cool the suction pump 18 using the nitrogen-enriched air discharged by the exhaust fan 20.

The LNG supplied to the LNG engine 2 is the LNG tank 22.
It is stored in. The LNG in the LNG tank 22 is taken out to the fuel supply pipe 26 via the take-out valve 24. The fuel supply pipe 26 has a heat insulating structure and communicates with a mixer 28 provided in the middle of the intake pipe 8. In the fuel supply pipe 26, a filter 30 for filtration and a solenoid valve 3 for shutting off LNG are sequentially installed from the LNG tank 22 side.
2, a vaporizer 34 for LNG vaporization, which will be described later, and a regulator 36 for LNG pressure adjustment.

The LNG in the LNG tank 22 is taken out to the fuel supply pipe 26 via the take-out valve 24, vaporized by the vaporizer 34, regulated by the regulator 36 and supplied to the mixer 28. In this mixer 28, LNG is mixed with the oxygen-enriched air produced by the oxygen-enriching device 12 to produce an air-fuel mixture. The air-fuel mixture is metered by the intake throttle valve 38, and the combustion chamber 6
Is supplied to and burned. The exhaust gas generated by combustion is exhausted to the outside by the exhaust passage 42 of the exhaust pipe 40.

The LNG engine 2 uses the latent heat of vaporization of LNG vaporized by the vaporizer 34 to cool the intake air.

That is, as shown in FIG. 2, the vaporizer 34 is provided in the air cleaner 4 of the LNG engine 2.

The air cleaner 4 has a filter element inside the case 44.
46 is held by packing 48. Case 44 is
It is composed of a first case member 44-1 and a second case member 44-2. An intake port 50 is provided between the first case member 44-1 and the second case member 44-2 and the second case member 44-2 is formed. 2 is provided with an air supply port 52. The intake port 50 is provided so as to communicate with the atmosphere. The air supply port 52 is provided so as to communicate with the intake passage 10 of the intake pipe 8. The filter element 46 is held by the first case member 44-1 and the second case member 44-2 by the packing 48 so as to separate the intake port 50 and the air supply port 52, and the intake chamber is internally provided. 54 are divided and provided.

The vaporizer 34 includes a heat transfer pipe 56 provided in the middle of the fuel supply pipe 26, and a heat transfer fin 58 provided in the heat transfer pipe 56. The vaporizer 34 is a heat transfer pipe provided in the intake chamber 54 of the air cleaner 4 in the middle of the fuel supply pipe 26.
56 and heat transfer fins 58 are arranged.

As a result, the vaporizer 34 is provided in the intake chamber 54 of the air cleaner 4 with the case 44 of the air cleaner 4 as a common component, as a case that is a component that covers the outer shell.

 Next, the operation will be described.

The LNG in the LNG tank 22 is taken out to the fuel supply pipe 26 via the take-out valve 24, vaporized by the vaporizer 34, regulated by the regulator 36 and supplied to the mixer 28.

At this time, the intake air filtered by the filter element 46 from the intake port 50 of the air cleaner 4 and sucked into the intake chamber 54 vaporizes the LNG by heat exchange with the LNG of the vaporizer 34 and is cooled by the latent heat of vaporization of this LNG. . The cooled intake air is increased in oxygen concentration by the oxygen enricher 12, is mixed with LNG by the mixer 28 to generate a mixture, and is supplied to the combustion chamber 6 for combustion. The exhaust gas generated by combustion is exhausted to the outside by the exhaust passage 42 of the exhaust pipe 40.

As described above, by cooling the intake air, it is possible to increase the density and improve the output, and also to cool the wall surface and the residual gas in the combustion chamber 6 to prevent the occurrence of abnormal combustion.

Further, the vaporizer 34 is provided in the intake chamber 54 of the air cleaner 4.
By providing the air cleaner 4, the cooling efficiency of the intake air can be improved by exchanging heat between the LNG and the intake air in the intake chamber 54 of the air cleaner 4, and the vapor cleaner 34 is integrally formed with the air cleaner 4. Four
Since the case 44 is shared, the volume and weight of the vaporizer 34 can be reduced, and the case that is a constituent member of the vaporizer 34 can be eliminated.

Therefore, the vaporization latent heat of LNG can be used to efficiently cool the intake air, and the vaporizer 34 that vaporizes LNG can be made smaller and lighter and the cost can be reduced.
When the LNG engine 2 is mounted as a prime mover of a vehicle or the like, the inconvenience of layout in the engine room and the inconvenience of cost increase can be avoided, and obstacles to practical use of the LNG engine vehicle can be solved.

In addition, the oxygen enrichment device 12 includes the intake passage 10 of the oxygen enrichment membrane 16.
An exhaust fan 20 is provided in the main body 12 in order to discharge the nitrogen-enriched air having a high nitrogen concentration generated on the upstream side. Downstream of the exhaust fan 20, the suction pump 18
Is oriented to. This makes it possible to cool the suction pump 18 using the nitrogen-enriched air discharged by the exhaust fan 20. For this reason, when the cooled intake air passes through the suction pump 18, it is possible to prevent the suction pump 18 from increasing the temperature.

[Effect of device]

As described above, according to the present invention, by providing the vaporizer for vaporizing LNG in the air cleaner of the LNG engine, it is possible to improve the cooling efficiency of the intake air by exchanging heat between the LNG and the intake air in the air cleaner. At the same time, the volume and weight of the vaporizer can be reduced and the components can be eliminated by sharing the case of the air cleaner.

Therefore, the latent heat of vaporization of LNG can be used to efficiently cool the intake air, and the vaporizer that vaporizes LNG can be made smaller and lighter and the cost can be reduced.
When the G engine is mounted as a prime mover of a vehicle or the like, it is possible to avoid the inconvenience that the layout in the engine room becomes difficult and the inconvenience that causes the cost increase, and it is possible to solve the obstacle to the practical use of the LNG engine vehicle.

Further, an exhaust fan for discharging the nitrogen-enriched air having a high nitrogen concentration generated on the upstream side of the intake passage of the oxygen-enriched film is provided, and the downstream side of the exhaust fan is provided so as to be directed to the suction pump. As a result, the suction pump can be cooled by utilizing the nitrogen-enriched air discharged by the exhaust fan. Therefore, when the cooled intake air passes through the suction pump, it is possible to prevent the temperature of the suction pump from rising.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is a schematic configuration diagram showing an intake cooling structure of an LNG engine, and FIG. 2 is an LNG.
FIG. 3 is an enlarged cross-sectional view of a main part of an intake air cooling structure of an engine. FIG. 3 shows a conventional example and is a schematic configuration diagram of an intake air cooling structure of an LNG engine. In the figure, 2 is an LNG engine, 4 is an air cleaner, and 6
Is a combustion chamber, 8 is an intake pipe, 0 is an intake passage, 12 is an oxygen enrichment device, 22 is an LNG tank, 26 is a fuel supply pipe, 28 is a mixer, 34
Is a vaporizer, 36 is a regulator, 38 is an intake throttle valve,
40 is an exhaust pipe, 42 is an exhaust passage, 44 is a case, 46 is a filter element, 48 packing, 50 is an inlet, 52 is an air inlet,
54 is an intake chamber, 56 is a heat transfer tube, and 56 is a heat transfer fin.

Claims (1)

(57) [Scope of utility model registration request] 1. An intake air cooling structure for an LNG engine, which cools intake air by utilizing latent heat of vaporization of LNG vaporized by a vaporizer, wherein the vaporizer is provided in an air cleaner of the LNG engine, and combustion of the air cleaner and the LNG engine is performed. An oxygen enrichment device equipped with an oxygen enrichment film that selectively permeates oxygen is provided in an intake passage communicating with the chamber, and an intake passage downstream of the oxygen enrichment device is provided with an upstream side of the oxygen enrichment film. A suction pump that generates a pressure difference between the downstream side and the oxygen-enriched film to generate oxygen-enriched air is provided downstream of the oxygen-enriched film, and the nitrogen-rich air generated upstream of the oxygen-enriched film is installed. An intake air cooling structure for an LNG engine, characterized in that an exhaust fan for exhausting the converted air is provided, and a downstream side of the exhaust fan is provided so as to face the suction pump.