JP2006348917A - Fuel supply device for gas engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply gasified fuel to a mixer from a time of gas engine start and suppress wasteful heat consumption of an electric heater regardless of pressure of liquefied fuel in a fuel supply device for a gas engine. <P>SOLUTION: The fuel supply device for the gas engine is a fuel supply device provided with the electric heater 20 heating liquefied fuel delivered from a liquefied fuel supply source 16 and making the same gasified fuel, a pressure regulator 10 regulating pressure of the gasified fuel, and the mixer 3 mixing gasified fuel of regulated pressure with air and supplying the same to the gas engine E, is provided with a first temperature sensor 21 detecting temperature of liquefied fuel of the liquefied fuel supply source 16, a second temperature sensor 22 detecting temperature of gasified fuel heated and gasified by the electric heater 20, and a control device 20 controlling operation of the electric heater 20 to keep detection temperature of the second temperature sensor 22 higher than detection temperature of the first temperature sensor 21 by a predetermined value S. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention comprises a heating means for heating a liquefied fuel sent from a liquefied fuel supply source to make it a vaporized fuel, a pressure regulator for adjusting the pressure of the vaporized fuel, and mixing the pressure-adjusted vaporized fuel with air. The present invention relates to improvement of a fuel supply device for a gas engine including a mixer for supplying the gas engine.

Conventionally, the following fuel supply devices for gas engines are known.
(1) As a heating means for heating the liquefied fuel, heat generated by the gas engine is used (see Patent Document 1).
(2) An electric heater with a thermostat is used as the heating means.
JP-A-10-122056

  By the way, in the case of (1) above, until the gas engine warm-up operation is completed, it is not possible to obtain the amount of heat sufficient to vaporize the liquefied fuel from the gas engine. It is necessary to heat the liquefied fuel by means, for example, an electric heater, and the configuration of the entire apparatus becomes complicated after all. Further, when the gas engine is operated at a high load, the amount of generated heat is particularly increased, and the internal pressure of the liquefied fuel conduit of the electric heater system is greatly increased. Therefore, it is necessary to configure the conduit to be an expensive high-pressure type.

  In the case of the above (2), in order to vaporize the liquefied fuel even when the liquefied fuel is at a high pressure, it is necessary to set the thermostat of the electric heater to a high off temperature (the required vaporization temperature of the liquefied fuel is As the pressure increases.) Therefore, when the liquefied fuel is at a low pressure, wasteful consumption of heat from the electric heater is increased.

  The present invention has been made in view of such circumstances. An electric heater is used so that vaporized fuel can be supplied to the mixer from the start of the gas engine, and the pressure of the liquefied fuel is high or low. An object of the present invention is to provide a fuel supply device for a gas engine that can suppress wasteful consumption of heat in an electric heater.

  In order to achieve the above object, the present invention provides a heating means for heating a liquefied fuel sent from a liquefied fuel supply source into a vaporized fuel, a pressure regulator for adjusting the pressure of the vaporized fuel, and a pressure-adjusted pressure regulator. A gas engine fuel supply device comprising: an electric heater that constitutes the heating means; and a temperature of the liquefied fuel from the liquefied fuel supply source. A first temperature sensor; a second temperature sensor for detecting a temperature of vaporized fuel heated and vaporized by the electric heater; and a temperature detected by the second temperature sensor is a predetermined value or higher than a temperature detected by the first temperature sensor. Thus, a first feature is that a control device for controlling the operation of the electric heater is provided.

  According to the present invention, in addition to the first feature, the control device may be configured such that the temperature detected by the second temperature sensor is a temperature obtained by adding a predetermined value to the temperature detected by the first temperature sensor. The second feature is that the operation is controlled.

  Furthermore, in addition to the first or second feature, the present invention attaches the first temperature sensor to an outside of a cylinder as the liquefied fuel supply source, and detects the temperature of the cylinder as the temperature of the liquefied fuel. This is the third feature.

  According to the present invention, in addition to the first or second feature, the first temperature sensor is attached to an outside of a liquefied fuel conduit connected to an outlet of the liquefied fuel supply source, and the temperature of the liquefied fuel conduit is set as described above. The fourth feature is that the temperature of the liquefied fuel is detected.

  The control device corresponds to an electronic control unit 23 in an embodiment of the present invention described later, and the liquefied fuel supply source corresponds to a fuel cylinder 16.

  According to the first feature of the present invention, by operating the electric heater, the liquefied fuel can be vaporized from the start of the gas engine and supplied to the mixer, so that the gas engine can be operated normally. In addition, the control device controls the operation of the electric heater so that the temperature detected by the second temperature sensor is equal to or higher than the temperature detected by the first temperature sensor, so that the electric power can be controlled regardless of the pressure of the liquefied fuel. It is possible to suppress wasteful heat consumption at the heater and to prevent an unnecessary increase in the internal pressure of the vaporized fuel conduit.

  Further, according to the second feature of the present invention, the operation control of the electric heater by the control device can be performed easily and accurately, and thereby wasteful heat consumption in the electric heater can be suppressed accurately.

  Furthermore, according to the third feature of the present invention, the first temperature sensor is configured to be a high pressure type by indirectly detecting the temperature of the liquefied fuel through the cylinder of the liquefied fuel supply source by the first temperature sensor. There is no need to do this, and cheaper ones are enough.

  According to the fourth aspect of the present invention, the first temperature sensor needs to be configured as a high pressure type by indirectly detecting the temperature of the liquefied fuel through the liquefied fuel conduit by the first temperature sensor. There is no need for an inexpensive one.

  Embodiments of the present invention will be described below based on preferred embodiments of the present invention shown in the drawings.

  FIG. 1 is a fuel supply system diagram of a gas engine equipped with a fuel supply device according to a first embodiment of the present invention, FIG. 2 shows a second embodiment of the present invention, a corresponding view with FIG. 1, and FIG. It is a diagram which shows the relationship between the liquefied fuel vapor pressure characteristic of a cylinder, and vaporization required temperature.

  First, the first embodiment of the present invention shown in FIG. 1 will be described. The gas engine E is used for driving a generator, for example. The gas engine E is equipped with a mixer 3 having an intake passage 2 communicating with the intake port 1, and an air cleaner 4 for filtering intake air passing through the intake passage 2 is connected to the mixer 3.

  The mixer 3 is provided with a throttle valve 5 that opens and closes the intake passage 2 and a fuel nozzle 6 that opens to the intake passage 2 on the upstream side of the throttle valve 5, and a vaporized fuel conduit 8 that communicates with the fuel nozzle 6. The upstream end is connected to the fuel outlet 10 a of the pressure regulator 10. A vaporization chamber 15 is provided on the fuel inlet side of the pressure regulator 10, and a liquefied fuel conduit 17 extending from a cassette type fuel cylinder 16 in which a fuel inlet 15 a of the vaporization chamber 15 is filled with liquefied fuel (for example, liquefied butane gas). Are connected at their downstream ends.

  An electric heater 20 is attached to one side of the vaporizing chamber 15, and the liquefied fuel introduced into the vaporizing chamber 15 is heated and vaporized by the operation of the electric heater 20. The pressure regulator 10 adjusts the high-pressure vaporized fuel sent from the vaporization chamber 15 to atmospheric pressure.

  A first temperature sensor 21 is attached to the outside of the fuel cylinder 16, and the temperature of the fuel cylinder 16 is detected as the temperature of the liquefied fuel inside the first temperature sensor 21. A second temperature sensor 22 is attached to the outside of the vaporizing chamber 15, and the temperature of the vaporizing chamber 15 is detected by the second temperature sensor 22 as the temperature of vaporized fuel inside the second temperature sensor 22. The detected temperatures of the first and second temperature sensors 21 and 22 are sent as electric signals to the electronic control unit 23, and the detected temperature of the second temperature sensor 22 is based on these signals. The operation of the electric heater 20 is controlled so as to be a temperature obtained by adding a predetermined value S to the temperature detected by the sensor 21.

  FIG. 3 shows the relationship between the liquefied fuel vapor pressure characteristic of the fuel cylinder 16 and the vaporization required temperature. As is clear from the figure, the temperature of the liquefied fuel in the fuel cylinder 16 rises as the liquefied fuel pressure increases. The vaporization required temperature of the liquefied fuel also rises as the liquefied fuel pressure increases. Moreover, the difference S between the liquefied fuel temperature and the vaporization required temperature is slightly constant on the low liquefied fuel pressure side, but is substantially constant. In the electronic control unit 23, the predetermined value S added to the temperature detected by the first temperature sensor 21 uses the difference S between the liquefied fuel temperature and the vaporization required temperature on the low liquefied fuel pressure side.

  Next, the operation of this embodiment will be described.

  During the operation from the start of the gas engine E, the high-pressure liquefied fuel delivered from the fuel cylinder 16 is introduced into the vaporizing chamber 15 through the liquefied fuel conduit 17 and is heated and vaporized by the operation of the electric heater 20 in the chamber 15. Is done. The vaporized fuel is adjusted to atmospheric pressure by the pressure regulator 10 and then supplied to the fuel nozzle 6 of the mixer 3 through the vaporized fuel conduit 8. In the intake passage 2 of the mixer 3, a mixture of the fuel sprayed from the fuel nozzle 6 and the air filtered by the air cleaner 4 is generated and supplied to the gas engine E while the flow rate is controlled by the throttle valve 5. The Thus, the gas engine E can be normally operated from the time of starting.

  Moreover, the electric heater 20 is operated so that the vaporized fuel temperature detected by the second temperature sensor 22 becomes a temperature obtained by adding a predetermined value S to the liquefied fuel temperature detected by the first temperature sensor 21. Therefore, it is possible to easily and accurately suppress wasteful heat consumption in the electric heater 20 regardless of the level of the pressure of the liquefied fuel, and to use the internal pressure of the liquefied fuel conduit 17 of the electric heater 20 system. Can be reliably prevented.

  At this time, since the first temperature sensor 21 is attached to the outside of the fuel cylinder 16 and detects the liquefied fuel temperature indirectly via the fuel cylinder 16, the first temperature sensor 21 is configured as a high pressure type. There is no need, and a cheap one is sufficient.

  Next, a second embodiment of the present invention shown in FIG. 2 will be described.

  This second embodiment has the same configuration as the previous embodiment except that the first temperature sensor 21 is attached to the outside of the liquefied fuel conduit 17 in the vicinity of the outlet of the fuel cylinder 16, and in FIG. Parts corresponding to the examples are denoted by the same reference numerals, and redundant description is omitted.

  According to the second embodiment, since the temperature of the liquefied fuel is indirectly detected near the outlet of the fuel cylinder 16 via the liquefied fuel conduit 17, the first temperature sensor 21 is also configured as a high pressure type in this case. There is no need, and a cheap one is sufficient.

  The present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the invention.

1 is a fuel supply system diagram of a gas engine including a fuel supply apparatus according to a first embodiment of the present invention. FIG. 4 is a diagram corresponding to FIG. 1 showing a second embodiment of the present invention. The diagram which shows the relationship between the liquefied fuel vapor pressure characteristic of a cassette type cylinder, and vaporization required temperature.

Explanation of symbols

E ... Gas engine 3 ... Mixer 8 ... Vaporized fuel conduit 10 ... Pressure regulator 15 ... Vaporization chamber 16 ... Liquid fuel supply source (Fuel) Cylinder)
17 ... Liquefied fuel conduit 20 ... Electric heater 21 ... First temperature sensor 22 ... Second temperature sensor 23 ... Control device (electronic control unit)

Claims (4)

A heating means (20) for heating the liquefied fuel sent from the liquefied fuel supply source (16) to make it vaporized fuel, a pressure regulator (10) for adjusting the pressure of the vaporized fuel, and the pressure-adjusted vaporized fuel A fuel supply device for a gas engine, comprising: a mixer (3) that mixes the gas with air and supplies the gas to the gas engine (E);
Heated and vaporized by the electric heater (20) constituting the heating means, the first temperature sensor (21) for detecting the temperature of the liquefied fuel from the liquefied fuel supply source (16), and the electric heater (20) The second temperature sensor (22) for detecting the temperature of the vaporized fuel, and the temperature detected by the second temperature sensor (22) is set to be equal to or higher than a predetermined value (S) from the temperature detected by the first temperature sensor (21). A fuel supply device for a gas engine, comprising: a control device (23) for controlling the operation of the electric heater (20). The fuel supply device for a gas engine according to claim 1,
The controller (23) operates the electric heater (20) so that the temperature detected by the second temperature sensor (22) is a temperature obtained by adding a predetermined value to the temperature detected by the first temperature sensor (21). A fuel supply device for a gas engine, characterized by being configured to control the engine. The fuel supply device for a gas engine according to claim 1 or 2,
The first temperature sensor (21) is attached to the outside of the cylinder (16) as the liquefied fuel supply source, and the temperature of the cylinder (16) is detected as the temperature of the liquefied fuel. , Fuel supply device for gas engine. The fuel supply device for a gas engine according to claim 1 or 2,
The first temperature sensor (21) is attached to the outside of the liquefied fuel conduit (17) connected to the outlet of the liquefied fuel supply source (16), and the temperature of the liquefied fuel conduit (17) is the temperature of the liquefied fuel. A fuel supply device for a gas engine, characterized by being detected as:

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