JP2002206733A - Method and equipment for supplying liquid fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To know a state of supply of liquid fuel without using a flow meter. SOLUTION: A pressure gage 4 is fitted to an accumulator 3 fitted to piping 7 connecting a fuel supply pump 2 and a combustion burner 5. The amount of supply of the liquid fuel is known by monitoring the pressure of the accumulator continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for stably burning liquid fuel, and more particularly to a method and apparatus for stably supplying liquid fuel.

[0002]

2. Description of the Related Art In a burner combustion apparatus for continuously supplying liquid fuel, if a sudden change in the fuel supply amount occurs due to equipment trouble or pipe blockage, an incomplete combustion state occurs, and in some cases, misfire, explosion, or pollution occurs. cause. For this reason, monitoring of the fuel supply amount is the most important in operation management, and it is required to quickly grasp the occurrence of abnormality and take appropriate measures.

Conventionally, the supply state of liquid fuel has been measured and grasped by a flow meter. However, the detection of the flow rate of the fuel including the minute flow rate and the fuel containing the solid matter by the flow meter may cause the flow meter to be clogged or lack the stability of the flow rate indication,
It was very difficult. Therefore, for the control of the flow rate of the fuel including the minute flow rate and the solid matter, the fuel supply amount is controlled by the set flow rate value determined by the pump performance curve using the positive displacement pump without using the flow meter.

[0004] In managing the fuel supply amount by the above method, it is difficult to grasp whether the fuel supply is actually being performed stably. For example, an accumulator installed to prevent pulsation of a positive displacement pump accumulates fluctuations in pipe pressure due to clogging or disconnection of the tip of the burner. was there.

This phenomenon has directly and suddenly caused a misfire or incomplete combustion. Further, even if the flow meter is mounted, there is a problem that the display of the flow meter itself has a large error and lacks stability, and further, the fuel supply is stopped due to clogging of the flow meter itself.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and particularly to a method and an apparatus for stably supplying liquid fuel in a small-scale combustion apparatus having a fuel supply rate of less than 50 liters per hour. Is provided.

[0007]

In order to solve the above-mentioned problems, the means for detecting the fuel supply amount and stabilizing the combustion according to the present invention is characterized by using a positive displacement pump to supply a liquid fuel containing solid matter and requiring heating. In a fuel supply device that supplies pressurized air to a burner at a flow rate of less than 50 liters per hour, a pressure gauge is attached to an accumulator for preventing pulsation installed in a pipe between the pump and the burner, and pressure is continuously monitored. And

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A feature of the present invention is that a pressure gauge is attached to an accumulator between a pump and a burner, particularly in a fuel supply device for supplying a liquid fuel containing a solid substance to a burner by pressurization. Pressure monitoring. For example, when a positive displacement pump is used as the fuel pressurizing source, even if a pressure gauge is attached to the piping without an accumulator, the pressure gauge detects the pulsation of the pump and the flow rate display value is not stable. Also, the fuel pulsation propagates to the burner, and the fuel injection from the burner tip nozzle also pulsates,
Unstable combustion results in combustion that is not preferable.

Therefore, an accumulator is installed in a pipe connecting the fuel supply pump and the burner, and a pressure gauge is attached thereto. The pressure source of the accumulator according to the invention is air or other compressed gas. Thereby, even in the fuel supply by the positive displacement pump, the compressed gas in the accumulator absorbs the pulsation, and stable fuel injection can be achieved from the tip of the burner. On the other hand, the pressure gauge for detecting stable combustion is attached to the gas portion above the accumulator, so that the compressed gas in the accumulator completely absorbs the pulsation and exhibits a stable pressure indication value.

If the pressure attached to the accumulator rises due to these effects, a decrease in the combustion flow rate, such as clogging of the burner tip, may cause a misfire. Conversely, if the increased pressure drops sharply, an excessive flow state due to the elimination of clogging of the burner tip can be assumed, and incomplete combustion can be easily found. As described above, since the pressure fluctuation indicates the flow rate fluctuation, the combustion flow rate fluctuation can be detected, and further, the combustion state of the liquid fuel can be easily grasped. Also,
Since the operating state is detected based on the pressure, the device itself does not become blocked or erroneously indicated, unlike a flow meter, to directly cause a trouble.

[0011] The method and apparatus of the present invention are also particularly effective for relatively small combustion systems with a fuel supply of less than 50 liters per hour. The reason is that when the fuel supply rate is 50 liters per hour or more, the flow rate in the pipe can be secured to some extent, so that the shape of the flow rate detection unit can be variously processed to prevent the flow rate detection unit from being blocked. This is because the detection of the combustion flow rate by various flow meters is relatively possible as compared with the case where the flow rate is small. For this reason, the measures of the present invention are not necessarily required.

However, at a very low flow rate of less than 50 liters per hour, it is difficult to process the pipe itself, and it is physically difficult to obtain a flow velocity in the pipe of a certain value or more.
Stable detection with a flow meter is difficult.

In order to cope with this problem, for example, even if an extremely small flow meter is manufactured, the behavior of the indicated value of the flow meter is extremely sensitive due to external factors, and the flow meter can be used even with a minute solid or fine solids. The indicated value deviation is large, the true value cannot be grasped, and it is not practical. In addition, in some cases, the flowmeter itself may become blocked, directly triggering a misfire. Then, it is necessary to grasp the combustion flow rate stability by the means of the present invention.

Further, the pump, piping, accumulator, and valve according to the present invention can be heated by a heat medium. For this reason, the present invention can be applied to, for example, a fuel supply system for supplying molten sulfur while heating the fuel, which is not possible with a flow meter for a minute flow rate.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment to which the present invention is applied will be described below with reference to FIG. The fuel used was molten sulfur. This molten sulfur is dissolved by steam in the fuel tank 1 and is kept at about 140 ° C. The fuel supply pump 2 is a jacket heating type positive displacement (plunger) pump and has a capacity of 0 to 2
It is a variable type every 3 liters.

The combustion burner 5 is an air spray orifice burner. The pipe 7 connecting the fuel supply pump and the combustion burner is a jacket pipe, and is heated so that sulfur in the pipe is not solidified by steam. Further, in order to prevent fuel pulsation, an accumulator 3 is attached to the pipe, and jacket-type steam heating is also performed. The accumulator has a diameter of 8
It is 0 mm, 300 mm long and has a capacity of about 1.5 liters. This accumulator is filled with air.

The pressure gauge 4 is attached to the uppermost portion of this accumulator (the side opposite to the pipe). The display range is from 0 to 1 MPa. The safety valve 8 at the pump outlet
Was set to 0.6 MPa. The volume of the accumulator was set to about one-fifteenth of the maximum fuel flow rate (liter) per hour. By displaying the pressure detected by the pressure gauge on a DCS (pressure monitoring graph) 9, it is possible to grasp the fuel supply amount and whether the combustion state is stable.

When operating with such a device configuration,
The pressure of the accumulator at each flow rate varies depending on the fuel supply amount and the diameter of the burner tip used, but is about 0.02 MPa at 7 liters per hour and about 0.2 MPa at 22 liters per hour. The relationship between the flow rate and the pressure of the accumulator during normal operation is standardized, and if the pressure rises to twice the standard accumulator pressure in a short time, it can be determined that there is a sign of trouble such as burner chip blockage.

FIG. 2 shows an example of the relationship between time and pressure as an example.
Shown in In FIG. 2, part (a) shows stable combustion, and part (b)
The part is the state at the time of fuel supply decrease such as burner tip blockage,
Part (c) shows a state in which the clogging of the pipe is self-resolved and the fuel supply is excessive.

As described above, when the abnormal pressure is detected, in part (b), the operating load of the downstream equipment for the combustion gas treatment is reduced, the heat is supplemented by the pilot burner, and at the same time, the planned misfire system is established. Trim. If the pressure condition is not expected to be improved, immediately implement backup measures to the downstream equipment and extinguish the planned fire. With these measures, it is possible to sufficiently avoid sudden misfires.

In part (c), measures are taken to increase the operating load of the downstream equipment for the combustion gas treatment, and to increase the amount of combustion air, thereby preventing incomplete combustion and sudden misfires associated therewith. Can be prevented.

[0022]

According to the present invention, the supply state of a fuel containing a small amount of solid matter requiring heating can be easily grasped, and the liquid fuel can be supplied stably in a small-scale liquid fuel combustion apparatus.

[Brief description of the drawings]

FIG. 1 is a diagram of one embodiment of a liquid fuel supply method according to the present invention.

Fig. 2 Relationship between accumulator pressure and time
It is a schematic diagram of an example.

[Explanation of symbols]

 Reference Signs List 1 fuel tank 2 fuel supply pump 3 accumulator 4 pressure gauge 5 combustion burner 6 combustion furnace 7 piping 8 safety valve 9 DCS (pressure monitoring graph)

Claims (3)

[Claims] In a fuel supply apparatus for supplying liquid fuel to a burner by pressurization by a positive displacement pump, a pressure gauge is attached to an accumulator between the pump and the burner, and the pressure is continuously monitored, so that the flow rate of the liquid fuel is increased. A method for supplying a liquid fuel, characterized by detecting fluctuations in the liquid fuel. 2. A fuel supply device using a heating pipe for supplying a liquid fuel having a flow rate of less than 50 liters / hour to a burner by a positive displacement pump, wherein a pressure gauge is attached to an accumulator between the pump and the burner. A method for supplying a liquid fuel, characterized by detecting fluctuations in the flow rate of the liquid fuel by continuously monitoring the pressure. 3. A fuel supply device for supplying a liquid fuel to a burner by pressurization using a positive displacement pump, comprising: an accumulator between the pump and the burner; and a pressure gauge for measuring a pressure in the accumulator. Fuel supply device.