JP4893715B2 - Fuel separator - Google Patents

Description

  The present invention relates to a fuel separator.

  2. Description of the Related Art An in-vehicle fuel separation device that uses a fuel separation membrane to separate a raw material fuel into a high-octane fuel and a low-octane fuel is known (for example, see Patent Document 1 below). In such a fuel separator, the raw material fuel is supplied to one side of the fuel separation membrane, and the other side of the fuel separation membrane is set to a negative pressure. The fuel that has permeated the fuel separation membrane becomes high-octane fuel, and the fuel that has not permeated the fuel separation membrane becomes low-octane fuel.

  In the fuel separator as described above, the separation performance of the fuel separation membrane deteriorates due to secular change. The cause of this deterioration is thought to be that the pores of the fuel separation membrane are clogged due to structural destruction of the membrane itself, inflow of solids, or the like. When the fuel separation membrane deteriorates, the yield (yield) of the high-octane fuel decreases.

  In the fuel separation device described in Patent Document 1, when the amount of high-octane fuel produced is greater than a predetermined upper limit, it is determined that an abnormality has occurred due to damage to the fuel separation membrane, and the amount produced is a predetermined lower limit. When the value is smaller than the value, it is determined that an abnormality has occurred due to a decrease in the function of the fuel separation membrane.

JP-A-2005-140047 JP 2007-231878 A

  In the conventional fuel separator, the amount of high-octane fuel produced is measured from the change in the liquid level of the fuel tank that stores the high-octane fuel. However, for that purpose, it is necessary to measure the liquid level of the fuel tank with extremely high accuracy. Since the liquid level of the fuel tank during engine operation fluctuates, it is extremely difficult to measure the liquid level with such high accuracy.

  Further, the high octane fuel flows into the fuel tank from the fuel separator through the negative pressure line. Although it is conceivable to measure the amount of high octane fuel produced from the flow rate of the negative pressure line, it is difficult to measure with high accuracy in this case as well.

  For this reason, the conventional fuel separation device has a problem that the deterioration of the fuel separation membrane cannot be detected until the yield of the high octane fuel is greatly reduced.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a fuel separator that can accurately determine deterioration of a fuel separation membrane with a simple configuration.

In order to achieve the above object, a first invention is a fuel separation device comprising:
A fuel separator having a fuel separation membrane, and separating the raw fuel into a high octane fuel having a higher octane number than the raw fuel and a low octane fuel having a lower octane number than the raw fuel;
Raw material fuel density measuring means for measuring the density of the raw material fuel;
Low octane fuel density measuring means for measuring the density of the low octane fuel,
A deterioration determining means for determining deterioration of the fuel separation membrane based on the density measured by the raw material fuel measuring means and the density measured by the low octane fuel density measuring means;
It is characterized by providing.

  According to the first invention, the density of the raw fuel and the density of the low-octane fuel separated by the fuel separation membrane are measured, and the deterioration of the fuel separation membrane is determined based on those densities. it can. When the fuel separation membrane deteriorates and the yield of the high-octane fuel decreases, the octane number of the low-octane fuel increases, and the difference from the octane number of the raw fuel decreases. Octane number correlates with fuel density. When the difference in octane number between the raw material fuel and the low-octane fuel becomes small, the difference in density between the two becomes small. Therefore, the deterioration of the fuel separation membrane can be easily and accurately determined based on the difference in density between the two.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
FIG. 1 is a diagram showing a fuel separator according to Embodiment 1 of the present invention. The fuel separator of this embodiment is applied to an in-vehicle fuel supply device that supplies fuel to an engine (internal combustion engine) 10 mounted on a vehicle. The fuel tank 12 stores normal gasoline supplied from the outside. The normal gasoline octane number is, for example, 90 RON (Research Octane Number). Hereinafter, the gasoline stored in the fuel tank 12 is referred to as “raw fuel”.

  One end of a raw material fuel pipe 14 is connected to the fuel tank 12. A fuel pump 16 is provided in the middle of the raw material fuel pipe 14. The other end of the raw material fuel pipe 14 is connected to the fuel separator 30. The raw material fuel in the fuel tank 12 is transferred to the fuel separator 30 by the fuel pump 16.

  The fuel separator 30 divides the supplied raw material fuel into a high octane number fuel (for example, 103 RON) in which the content ratio of the high octane component is higher than that of the raw material fuel and a low octane number fuel (for example, the content ratio of the high octane number component is smaller than that of the raw material fuel). , 88RON).

  A fuel heater (not shown) is disposed in the middle of the raw material fuel pipe 14, and the raw material fuel is heated by the fuel heater and then supplied to the fuel separator 30.

  The fuel separator 30 has a housing made of a pressure vessel and a fuel separation membrane 301 installed in the housing. The internal space of the housing is divided into two compartments 302 and 303 by a fuel separation membrane 301. The raw material fuel from the raw material fuel pipe 14 flows into the compartment 302. The fuel separation membrane 301 has a property of selectively permeating aromatic components in the raw material fuel. As the amount of aromatic component increases, the octane number increases. For this reason, the fuel which permeate | transmitted the division 303 side becomes a high octane fuel, since content of an aromatic component increases. On the other hand, the fuel remaining on the compartment 302 side is a low-octane fuel because the content of the aromatic component is reduced.

  One end of a low-octane fuel pipe 32 is connected to the compartment 302 side of the fuel separator 30. A regulator 34 is installed in the middle of the low octane fuel pipe 32. The low-octane fuel separated by the fuel separator 30 passes through the low-octane fuel pipe 32, is regulated by the regulator 34, and then supplied to the engine 10.

  On the other hand, one end of a high octane fuel pipe 38 is connected to the compartment 303 side of the fuel separator 30. Further, an ejector (not shown) for generating a negative pressure in the compartment 303 is provided in the middle of the high octane fuel pipe 38. The high-octane fuel separated by the fuel separator 30 passes through the high-octane fuel pipe 38 and is sent to a storage section (not shown).

  A piping 42 branches from the raw material fuel piping 14. This pipe 42 is connected to a density measuring device 44. A pipe 46 branches off from the low octane fuel pipe 32. The pipe 46 is connected to the density measuring device 44. A pipe 40 is further branched from the low octane fuel pipe 32. This pipe 40 is connected to a fuel temperature measuring device 48. The density measuring device 44 can measure the density of the fuel by measuring the refractive index or dielectric constant of the fuel.

  The separation performance of the fuel separation membrane 301 deteriorates due to aging. It is considered that the cause of this deterioration is that the pores of the fuel separation membrane 301 are clogged due to structural destruction of the membrane itself, inflow of solids, or the like. When the fuel separation membrane 301 deteriorates, the yield (yield) of the high octane fuel decreases. When the fuel separation membrane 301 deteriorates, it is important to detect this early and accurately.

  In the present embodiment, the density measuring device 44 measures the density of the raw material fuel and the density of the low octane fuel, respectively, and determines the deterioration of the fuel separation membrane 301 based on the density difference.

  As described above, when the octane number of the raw material fuel is 90 RON and the fuel separation membrane 301 is normal, the octane number of the low octane number fuel flowing out from the fuel separator 30 is about 88 RON, for example. The octane number of the fuel correlates with the density of the fuel. For this reason, in the above case, there is a predetermined difference between the density of the raw fuel and the density of the low octane fuel.

  However, when the fuel separation membrane 301 is deteriorated, the separation performance is lowered, so that the amount of the aromatic component that permeates the compartment 303 side is reduced and the amount of the aromatic component that remains on the compartment 302 side is increased. As a result, the aromatic component content in the low-octane fuel flowing out from the low-octane fuel pipe 32 increases, and the octane number of the low-octane fuel increases. For this reason, the difference between the octane number of the raw material fuel and the octane number of the low octane number fuel becomes small. Therefore, the difference between the density of the raw material fuel and the density of the low octane fuel becomes small. Therefore, when it is detected that the difference between the density of the raw material fuel and the density of the low octane fuel is smaller than the normal value, it can be determined that the fuel separation membrane 301 is deteriorated.

  Specifically, the ECU 50 determines the deterioration of the fuel separation membrane 301 as follows. First, in the density measuring instrument 44, the density of the raw material fuel sent by the pipe 42 and the density of the low octane fuel sent by the pipe 46 are sequentially measured. Next, the difference between the two densities is compared with a predetermined determination value. In the comparison result, when the density difference is smaller than the determination value, it is determined that the fuel separation membrane 301 is deteriorated. Otherwise, it is determined that the fuel separation membrane 301 is normal.

  As described above, it is difficult to accurately measure the yield and yield of high-octane fuel. On the other hand, it is easy to accurately measure the fuel density. For this reason, according to the present embodiment, it is possible to easily and accurately determine the deterioration of the fuel separation membrane 301. Therefore, when the fuel separation membrane 301 is deteriorated, this can be detected at an early stage.

  In this embodiment, after confirming that the fuel separator 30 is normally warmed up based on the temperature of the low-octane fuel detected by the fuel temperature measuring device 48, the fuel separation membrane 301 is deteriorated. You may make it perform determination. As a result, erroneous determination can be reliably prevented.

  In the first embodiment described above, the density measuring device 44 measures the density of the raw material fuel so that the “raw material fuel density measuring means” in the first invention is the same as the density measuring device 44 is the low octane fuel. The "low octane number fuel density measuring means" in the first aspect of the present invention makes it possible for the ECU 50 to compare the difference between the density of the raw material fuel and the density of the low octane number fuel with the above judgment value. The “deterioration determination means” in the present invention is realized.

It is a figure which shows the fuel separator of Embodiment 1 of this invention.

Explanation of symbols

10 Engine 12 Fuel tank 14 Raw material fuel pipe 30 Fuel separator 301 Fuel separation membranes 302 and 303 Section 32 Low octane fuel pipe 38 High octane fuel pipe 50 ECU

Claims (1)

A fuel separator having a fuel separation membrane, and separating the raw fuel into a high octane fuel having a higher octane number than the raw fuel and a low octane fuel having a lower octane number than the raw fuel;
Raw material fuel density measuring means for measuring the density of the raw material fuel;
Low octane fuel density measuring means for measuring the density of the low octane fuel,
A deterioration determining means for determining deterioration of the fuel separation membrane based on the density measured by the raw material fuel measuring means and the density measured by the low octane fuel density measuring means;
A fuel separation device comprising:

Images