JPH01138357A - Supply of lpg - Google Patents

Abstract

PURPOSE:To prevent the deterioration of rubber parts and operation disorder of a valve, etc., by allowing the LPG which is sent out from an LPG source and preheated to pass through a tar collector, when the engine temperature is over a prescribed value, and by supplying said LPG into a vaporizer and separating the heavy material portion. CONSTITUTION:When a manual opening/closing valve 2 is opened during the engine operation, the LPG in a pressureproof container 1 is sent into a vaporizer 4 through a fuel conduit 3, and then decompressed and vaporized in a mixer 5 and mixed with air supplied from an air cleaner 6. In this case, in the fuel conduit 3, a preheater 9 and a filter 10 are installed in this order on the downstream side of the opening/closing valve 2, and the downstream side is branched into the first and second conduits 11 and 12, and connected with the vaporizer 4, and a tar collector 13 is installed in the first conduit 11. The LPG after preheating in the preheater 9 is allowed to pass through the first conduit 12 and tar is removed when the engine temperature is over a prescribed value, while, if the engine temperature is below a prescribed value, the LPG is allowed to pass through the second conduit 12 and directly introduced into the vaporizer 4.

Description

[Detailed Description of the Invention] (Industrial Application Field) The LPG delivery method of the present invention is mainly applied to automobile engines.
Used in systems that supply PG.

(Prior Art) As is well known, LPG generally contains a heavy substance called tar, which accumulates in various places during the time it is supplied from a pressure container to a paperizer and mixer to an engine, causing damage to rubber parts. deterioration.

This can cause malfunction of pulp and clogging of jets. As a countermeasure against this problem, it is known to install a tar removal device in the riser so that the heavy components accumulated inside the riser can be appropriately discharged.

(Problem to be solved by the invention) However, compared to the average private car, a commercial vehicle that uses LPG as fuel has a longer mileage and consumes more fuel. A large amount of fuel accumulates in various places in a short period of time, which can interfere with normal fuel supply.

Therefore, it is necessary to periodically disassemble and clean the fuel supply system, which is not only extremely troublesome.

There are problems such as extra costs required for maintenance.

In view of these circumstances, the present invention has been made with the object of providing a method that can appropriately supply LPG for a long period of time without the inconvenience of accumulating tar in the fuel supply system and preventing normal fuel supply. It is what was done.

(Means for Solving the Problems) The present invention provides a method for supplying LPG to an engine via a paperizer and a mixer.
The preheated LPG is preheated to vaporize at least a part of it, and when the temperature is below a predetermined temperature, the preheated LPG is fed into the paperizer as it is.

In order to solve the above problem, the preheated LPG is fed into the paperizer via the tar collector when the temperature is above a predetermined temperature.

That is, by first preheating the LPG sent out from the pressure container with engine cooling water or electrical resistance heat and vaporizing at least a portion of it, at least a portion of the heavy content contained in the LPG is vaporized, and the preheated LPG is heated. When the flow rate is lowered and the mixture is expanded at the same time, the heavy components entrained in a liquid state are separated due to the lowering of the flow rate, and the vaporized heavy components are liquefied again due to the temperature drop accompanying the expansion and are similarly separated. Therefore, by forming the tar collector in the shape of a container of an appropriate size, separation and removal of heavy components can be effectively performed.

Next, when the present invention is applied to an automobile engine, if the tar collector is installed in the engine room, it will be affected by the engine temperature. Therefore, when the engine temperature is low before completion of warm-up, the tar collector itself is also at a low temperature, and when the vaporized gas of the preheated LPG that flows in comes into contact with the wall, not only the heavy components but also the LPG are reliquefied. Put it away. In particular, when a method is adopted in which LPG is preheated using engine cooling water, the rate of vaporization is low when the engine temperature is low, so it easily returns to a liquefied state when it enters the tar collector.

Furthermore, if the tar collector is installed outside the engine room, it will be affected by the atmospheric temperature, so the LPG ft'4
Even if you preheat with air resistance heat, you can preheat LP with a tar collector when the temperature is low.
G reliquefies.

In this way, when LPG is reliquefied in the tar collector, it is mixed again with the heavy components that have been separated and sent to the paperizer.

Therefore, in the present invention, LPG preheating means is provided.

Depending on the installation location of the tar collector, when either the engine temperature, the atmospheric temperature, or both are higher than a predetermined temperature, LPG is sent to the paperizer through the tar collector,
When the temperature is lower than a predetermined temperature, the LPG is sent to the paperizer without passing through the tar collector. This switching of the fuel path is performed by controlling the opening/closing or direction of an electromagnetically driven control valve using, for example, an oscillation signal sent from an electronic control circuit.

Please note that LPG should not be passed through a tar collector (supply LPG only before the engine has warmed up or when the atmospheric temperature is extremely low).

Considering the total operating time of the engine, it is quite a short time and the amount of LPG consumed is small, so the amount of heavy components accumulated in the paperizer etc. is an acceptably small amount.

(Example) Examples of the present invention will be described based on the drawings.

When the manual on-off valve 2 is opened, the LPG in the pressure container 1 is sent to the paperizer 4 through the fuel conduit 3, vaporized under reduced pressure, mixed with the air that has passed through the air cleaner 6 in the mixer 5, and then transferred to the intake manifold 7. is supplied to engine 8 via a ladder.

The fuel conduit 3 has a preheater 9 and a filter l downstream of the on-off valve 2.
O in this order, and further branched in parallel into a first conduit 11 and a second conduit 12 on the downstream side thereof and connected to the paperizer 4. The first conduit 11 has a tar collector 13 and electromagnetically driven control valves 14, 15 arranged before and after the tar collector 13,
The second conduit 12 has an electromagnetically driven control valve 16;
The opening and closing of these control valves 14, 15, and 16 are controlled by drive signals sent from an electronic control circuit 17.

The electronic control circuit 17 controls throttle valve opening, engine rotation speed,
Engine operating conditions such as engine temperature are input as parameters, and in some cases, atmospheric temperature and temperatures of the preheater 9 and paperizer 4 are input as parameters, and when the engine temperature or atmospheric temperature is below a predetermined temperature, other parameters are used as a reference. First conduit 110 control valve 14
．． 15 is closed and the second conduit 120 control valve 16 is opened. When the temperature is above a predetermined temperature, the first conduit 110 control valve 1
4.15 v Open the second conduit 120 control valve 16, and when the engine is stopped, all the control valves 14, 15
．． 16 is closed. In some cases, temperature switches may be used to open and close the drive circuits of the control valves 14, 15, 16 to effect this operation.

Alternatively, a control valve may be provided at a branch point and a confluence point of the two conduits 11, 12 to switch and close the flow path of the preheated LPG.

(Effects of the Invention) According to the present invention, heavy components are effectively separated by preheating LPG and causing the tar collector to lower the flow rate and expand it. This not only simplifies maintenance because there is no need to worry about deterioration, malfunction of pulp, or clogging of jets, but it also ensures that LPG is properly supplied over a long period of time and does not interfere with engine operation. Also, at low temperatures, the preheated LPG is sent directly to the paperizer, so there is no need to worry about entraining the heavy components accumulated in the tar collector.

This ensures that the engine remains in good condition for a long period of time over the entire operating range.

[Brief explanation of the drawing]

The drawing is a system diagram showing an embodiment of the present invention. l...Pressure vessel, 3...Fuel conduit, 4
...Paperizer,'5...Mixer,
8...Engine, 9...Preheater, 11
......First conduit, 12...Second conduit, 13...Tar collector, 14,15゜16
・・・・・・Control valve. −・、

Claims (1)

[Claims] When LPG is supplied to the engine via a paperizer and a mixer, the LPG sent out from the pressure container is preheated to vaporize at least a portion of it, and when the temperature is below a predetermined temperature, the preheated LPG is directly fed to the paperizer and heated to a predetermined temperature. An LPG supply method characterized in that when the temperature is higher than that, the preheated LPG is sent to a paperizer via a tar collector.