JPH0560320A - Fuel feeder of combustion apparatus - Google Patents

Abstract

PURPOSE:To directly, accurately control the fuel flow rate by a method wherein the rate of fuel feed to a nozzle is determined according to flow path areas of a throttling device and differential pressures across the throttling device. CONSTITUTION:A return pipe valve 12 is provided on a return pipe 5 and just before a conjunction point 9 to vary the flow path area, and a feed pipe valve 17 is mounted on an oil feed pipe 2 upstream the conjunction 9 to vary the flow path area of the feed pipe 2. The valve 17 is driven back and forth by a motor 21. A diaphragm 30 is able to move in a direction perpendicular to the plane of the diaphragm 30, and the inner pressures at the upstream and downstream sides of the feed pipe 2 are respectively applied on the upper and lower faces of the diaphragm 30. The differential pressure across the valve 17 acts on the diaphragm 30, and the flow path area of the return pipe 5 is increased or reduced so as to balance the differential pressure with the repellent force of a spring 13. As a result, the differential pressure across the valve 17 is kept constant. Therefore, the flow path area of the valve 17 is controlled by the motor 21 and line flow rate is directly, accurately controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention constantly feeds a fixed amount of liquid fuel to a spray nozzle, returns a part of the liquid fuel from the nozzle, and adjusts the amount of return to adjust the flow rate of fuel used for combustion in the nozzle. The present invention relates to a fuel supply device for a combustion device.

[0002]

2. Description of the Related Art FIG. 3 shows a fuel supply device for a conventional combustion device, in which a fixed amount of oil introduced from an oil tank 1 to an oil feed pipe 2 is constantly delivered to a spray nozzle 4 by a fuel pump 3. There is. However, a part of the petroleum oil sprayed in the tip portion of the spray nozzle 4 passes through the flow rate adjusting valve 6 via the oil return pipe 5, and is returned to the oil feed pipe 2 upstream of the fuel pump 3.

In this way, the amount of petroleum injected forward from the spray nozzle 4 and supplied to the combustion section is determined by the oil return pipe 5.
It is controlled by adjusting the amount of oil back.

[0004]

However, in the fuel supply device of the conventional combustion apparatus as described above, the flow rate of the fuel used for combustion is estimated from the flow rate of the fuel returned from the nozzle. If the flow rate (discharge amount) of the pump 3 and the nozzle diameter of the spray nozzle 4 are varied, the flow rate of the fuel supplied to the combustion section is considerably inaccurately controlled.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a fuel supply device for a combustion device, which can directly and accurately control the flow rate of fuel used for combustion.

[0006]

In order to achieve the above object, a fuel supply device for a combustion apparatus according to the present invention interposes a constant amount of liquid fuel from a feed pipe to a nozzle in the middle of the feed pipe. The inserted fuel pump, a return pipe for returning a part of the fuel from the nozzle to a confluence portion that merges with the feed pipe on the upstream side of the fuel pump, and for changing the flow passage area of the return pipe. A return pipe valve, a throttle portion that narrows the flow passage area of the feed pipe on the upstream side of the confluence portion, and the return pipe passage that operates by the differential pressure in the feed pipe upstream and downstream of the throttle portion. And a differential pressure operating means for controlling the operation of the valve.

The differential pressure operating means controls the operation of the return line valve so that the differential pressure in the feed pipe on the upstream side and the downstream side of the throttle portion is kept constant, and the throttle portion is controlled. May be provided with a valve for changing the flow passage area of the throttle portion, or the flow passage area of the throttle portion may be made constant and the differential pressure operating means may be provided with the feeds on the upstream side and the downstream side of the throttle portion. You may provide the differential pressure control means for controlling the differential pressure in a pipe.

[0008]

The flow rate of fuel consumed for combustion in the nozzle is determined by the flow passage area of the throttle portion of the feed pipe formed upstream of the confluence and the differential pressure between the upstream and downstream feed pipes of the throttle portion. Depends on

Therefore, the flow rate of the consumed fuel can be controlled by a valve that changes the flow passage area of the throttle portion of the feed pipe if the differential pressure across the throttle portion is kept constant. If it is kept constant, it can be controlled by the differential pressure control means for controlling the differential pressure across the throttle portion.

Then, the flow passage area of the return pipe is changed by the return pipe valve so that the flow rate of the consumed fuel becomes such a control value.

[0011]

Embodiments will be described with reference to the drawings. FIG. 1 shows a first embodiment of the present invention, in which the oil in the oil tank 1 is removed by a fuel pump 3 inserted in the middle of an oil feed pipe 2 that connects the oil tank 1 and the spray nozzle 4 to each other. A fixed amount is always sent to the spray nozzle 4 through the oil feed pipe 2.

A part of the petroleum oil sprayed in the tip portion of the spray nozzle 4 passes through the oil return pipe 5 to the oil feed pipe 2 from the merging portion 9 where it joins with the oil feed pipe 2 on the upstream side of the fuel pump 3. Will be returned.

Therefore, from the spray nozzle 4 to the oil return pipe 5
By changing the amount of petroleum returned through the spray nozzle 4, the amount of petroleum sprayed from the spray nozzle 4 to the combustion section 10 and provided for combustion is controlled.

On the oil return pipe 5, a ball-shaped return pipe valve 12 for changing the flow passage area of the oil return pipe 5 is provided with a compression coil spring 13 toward a valve seat 11 formed immediately before the confluence portion 9. It is urged by and arranged. Reference numeral 14 is a coil spring receiver, and 15 is a nut for adjusting the spring force of the compression coil spring 13.

In addition, a ball-shaped feed line valve 17 for changing the flow passage area of the oil feed pipe 2 is arranged on the oil feed pipe 2 upstream of the merging portion 9 and fixed to the tip of a rod 18. Has been done.

The feed line valve 17 is driven forward and backward by a motor 21 via a gear mechanism 20 toward a valve seat 19 formed on the downstream side of the feed line valve 17. A potentiometer 22 is attached to the other end of the rod 18 to detect the amount of axial displacement of the rod 18.
Based on the detection signal, the operation of the motor 21 is feedback-controlled by the control unit 23, and the flow passage area of the oil feed pipe 2 can be arbitrarily and accurately narrowed. 25 and 26
Is an O-ring for sealing and its receiving plate.

Reference numeral 30 denotes a diaphragm which is displaceable in the surface direction, and the inner surface and the outer surface thereof are arranged so that the internal pressures of the oil feed pipes 2 on the downstream side and the upstream side of the feed line valve 17 are applied. .. A rod 32 is inserted between the diaphragm receiving board 31 that receives the diaphragm 30 on the inner surface side and the return conduit valve 12 so as to be movable back and forth.

Therefore, a differential pressure across the feed conduit valve 17 is applied to the diaphragm 30, and the differential pressure acts against the biasing force of the compression coil spring 13 in the direction of opening the return conduit valve 12.

As a result, the return pipe valve 12 increases or decreases the flow passage area of the oil return pipe 5 so that the differential pressure applied to the diaphragm 30 and the biasing force of the compression coil spring 13 are balanced, and the return pipe valve 12 joins from the spray nozzle 4. The amount of oil returned to the section 9 is controlled so that the differential pressure across the feed line valve 17 is always kept constant.

According to the apparatus of the embodiment thus constructed, the flow rate Q of the oil flowing through the feed line valve 17 is the oil consumed by the spray nozzle 4, that is, the oil used for combustion in the combustion section 10. Is the flow rate itself.

The flow passage area of the feed line valve 17 is S,
If the differential pressure across it is ΔP, then Q = K · S · √ΔP, and since ΔP is constant, Q = K _A · S, and the flow rate of oil used for combustion is the flow of the feed line valve 17. It is determined only by the road area S. Note that K and K _A are constants.

Therefore, in this embodiment, by controlling the flow passage area S of the feed pipe valve 17 by the motor 21, the flow rate Q of the petroleum used for combustion is directly and accurately controlled and follows it. Then, the flow rate of the oil returned to the oil return pipe 5 changes.

FIG. 2 shows a second embodiment of the present invention. In the oil feed pipe 2 on the upstream side of the confluence portion 9, a throttle portion 41 having a constant flow passage area is formed and a diaphragm 30 is provided.
The force applied to the surface is changed by the solenoid magnet device 42 so that the pressure difference between the upstream side and the downstream side of the throttle portion 41 in the oil feed pipe 2 can be controlled.

[0024] In this case, the flow passage area of the throttle portion 41 S, when the ΔP of the differential pressure is Q = K · S · √ΔP, because S's is constant, Q = K _B · √ΔP next The flow rate of oil used for combustion is determined only by the differential pressure ΔP across the throttle portion 41. Note that K and K _B are constants.

Therefore, in this embodiment, the differential pressure ΔP across the throttle portion 41 is controlled by the solenoid magnet device 42.
By controlling the flow rate of oil used for combustion Q
Is controlled directly and accurately, and the flow rate of the oil returned through the oil return pipe 5 changes accordingly.

The present invention is not limited to the above embodiment, and for example, the drive of the feed line valve 17 of the first embodiment and the control of the differential pressure across the throttle portion 41 of the second embodiment are controlled. Any device may be used for the above.

[0027]

According to the fuel supply device for the combustion apparatus of the present invention, the flow rate of the fuel used for combustion in the nozzle is directly determined from the flow passage area of the throttle portion and the differential pressure across the nozzle, Since the return flow rate from the fuel cell changes only in accordance with it, the flow rate of the fuel used for combustion can be directly and accurately controlled, and one of the flow passage area of the throttle and the differential pressure across the throttle can be made constant. In this case, the flow rate of the fuel used for combustion can be accurately controlled by controlling only the other.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a configuration diagram of a second embodiment.

FIG. 3 is a configuration diagram of a conventional example.

[Explanation of symbols]

 2 Oil feed pipe 3 Fuel pump 4 Spray nozzle 5 Oil return pipe 9 Confluence part 12 Return pipe line valve 17 Feed pipe line valve 19 Valve seat 30 Diaphragm (differential pressure operation means) 41 Throttling part 42 Solenoid magnet device

Claims (3)

[Claims] 1. A fuel pump inserted in the middle of the feed pipe so as to constantly feed a fixed amount of liquid fuel to a nozzle, and a merging portion which joins the feed pipe upstream of the fuel pump. A return pipe for returning a part of the fuel from the nozzle, a return pipe valve for changing the flow passage area of the return pipe, and a throttle for narrowing the flow passage area of the feed pipe upstream of the merging portion. And a differential pressure operating means for controlling the operation of the return line valve by operating by the differential pressure in the feed pipe on the upstream side and the downstream side of the throttle portion, and the fuel for the combustion apparatus. Supply device. 2. The differential pressure operating means controls the operation of the return conduit valve so as to maintain a constant differential pressure between the upstream side and the downstream side of the feed pipe of the throttle portion, and controls the return passage valve to the throttle portion. Is provided with a valve for changing the flow passage area of the throttle portion.
A fuel supply device for the described combustion device. 3. The flow passage area of the throttle portion is constant, and the differential pressure operating means includes differential pressure control means for controlling the differential pressure in the feed pipe on the upstream side and the downstream side of the throttle portion. The fuel supply device for a combustion device according to claim 1, which is provided.