JP2718885B2 - Combustion amount adjustment device for combustor with return nozzle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray type fuel oil which is fed from a gun-type oil burner, a pulse burner or another return injection valve (hereinafter referred to as "return nozzle") through, for example, an electromagnetic pump. In a combustor that burns, a part of the flow rate from the pump is returned from the inside of the nozzle to the suction side of the pump in order to convert the combustion amount with the same nozzle, and the return amount is adjusted to increase or decrease the fuel injection from the nozzle. The present invention relates to a flow control device including an electromagnetic amplitude type flow control valve adapted to control a flow rate.

[0002]

2. Description of the Related Art As a prior art relating to a flow rate adjusting device for adjusting the amount of combustion in a combustor having a return nozzle as described above, there is a series of publications such as Japanese Patent Laid-Open No. 4-32608. Those disclosed in these publications are provided with an electromagnetic flow control valve (FC), and an AC component for preventing hysteresis of the electromagnetic flow control valve (FC) is superimposed on a drive current of the (FC). Water heater (A)
Wherein the frequency of the AC component is the same as the frequency of the AC driving the electromagnetic pump (P), and the phase of the AC component is different from the phase of the AC driving the electromagnetic pump (P). There is a statement in the claims to the effect.

Similarly, in a combustor having a return nozzle, when the flow rate of liquid fuel sprayed from the spray nozzle is reduced, air is not sucked in from the tip of the spray nozzle, and as a result, the spray flow rate is adjusted over a wide range. There is a prior art disclosed in Japanese Patent Application Laid-Open No. 5-223244 for the purpose of providing a fuel supply device for a combustion device that can perform the combustion.

[0004] Further, there is provided a spray nozzle for a combustor having a return nozzle similarly to the above, wherein even if the spray amount is small and the return flow rate is large, air is not trapped in the return pores. There is a prior art disclosed in Japanese Patent Application Laid-Open No. 4-295503, which has a problem of the configuration of the nozzle itself.

[0005]

The above-mentioned prior art, which is disclosed in Japanese Patent Laid-Open Publication No. Hei 4-32608,
The flow control valve (FC) shown in the figure is described in detail from the third line of the upper left column of the fourth page to the fourth line of the lower left column of the same page. This will be further described with reference to FIG. 5 of the present application in which FIG. 7 is transcribed.

Return oil from the spray nozzle (N) enters the valve FC from the return oil passage (43e) as shown by the arrow b, and supplies a required current to the solenoid (51) according to the required heat load of the hot water supply level (A). ) To advance and retreat the spherical valve element (45) supported by the valve element reciprocating rod (47) to adjust the flow rate of kerosene and to perform accurate combustion control of the burner (20).

However, the oil flowing from the fuel oil tank as shown by the arrow a and entering through the oil communication flow path (43a) is combined with the return oil narrowed down by the flow rate adjustment path (43) to join the oil downstream (43).
Via c), it is supplied to the nozzle (N) as shown by the arrow c '. In the middle of the communication flow path (43a) at this time, a flow rate adjustment flow path (43) bent in an L-shape via a valve seat (44), and further downstream on the downstream side, also bent in an L-shape. And the existence of the circular recess (48).

The return oil having a slightly higher pressure from the arrow b is throttled between the spherical valve body 45 and the valve seat 44, and the oil level of the fuel oil tank in the flow rate adjustment flow path 43 is higher than the suction side of the electromagnetic pump (P). When merging with a fluid having a relatively low pressure such as a negative pressure when the pressure is low, the dissolved gas body in the return oil is naturally easily vaporized, and the recess of the oil flow path to the electromagnetic pump (P) is formed. Is a place where the accumulated gas accumulates, and when the accumulated gas is released and reaches the electromagnetic pump (P), air bubbles in the suction valve may be blocked. The electromagnetic plunger pressurized between the springs and the discharge plunger articulated with the spring form a free piston, and when gas enters the pump, flow and pressure resistance are reduced as compared to liquid. So the stroke of these plungers Elongating to lead to pulsation changes of pressure of the discharge liquid and the flow rate along with noise. This naturally leads to an unbalanced air-fuel ratio, resulting in harmful gases from deflagration and incomplete combustion, and pollution with noise and vibration. FIG. 7 of the present application shows the fluctuation state of the fuel oil injection amount.

FIG. 7 shows this Japanese Patent Application Laid-Open No. 4-32608,
FIG. 3 is a diagram showing a variation in an injection amount from a nozzle, that is, a combustion oil amount in a case where an electromagnetic pump using the flow control valve (FC) shown in the figure and the return nozzle are provided.

In FIG. 7, the elapsed time t (1/1) is plotted on the horizontal axis.
18h, a pen recorder of 18 cm / h), and the vertical axis represents the injection amount Q (L / h) from the nozzle. The nozzle is 1.35
Gal / h, solenoid for flow control valve (FC) (51)
The applied current to the DC was 133 Hz DC, and the conduction period (ON time OT) during the cycle was 3.0, 3.5, 4.0, and 4.
5, 5.0, 5.5, 6.0, 6.5, 7.0 ms (1/1000 second)
And off is the time when the electricity is cut off to (FC) and the case where the full amount is ejected from the nozzle.

The fact that the applied current is set to 133 Hz DC means that a driving power supply for the electromagnetic pump (P) of this kind is usually 50 to 60 Hz of a commercial AC power supply after being half-wave rectified. In some cases, a power supply is used, but in any case, the resonance with the drive power supply cycle of the electromagnetic pump (P) is avoided, the cycle is shortened, the frequency is increased, and the pulsation of the return oil amount is suppressed. Nevertheless, the discharge pulsation of the fuel oil from the nozzle has the disadvantage that it is much larger than the return nozzle provided with the electromagnetic amplitude type flow control valve of the present invention, which will be described later, and the vibration and noise are large.

Further, the prior arts disclosed in the above-mentioned Japanese Patent Application Laid-Open Nos. 5-223244 and 4-295503, particularly when the return flow rate is increased in order to reduce the injection flow rate from the return nozzle. Means for preventing air from being sucked from the tip of the nozzle, means for preventing gas generation in the return flow path in the flow control valve for adjusting the return amount and the suction flow path to the pump, and this gas It is desired to prevent the pulsation, vibration, and noise from the nozzles from being crushed and mixed with the liquid to increase the speed and to perform the passage processing so as to prevent the pulsation, vibration, and noise from the nozzle, unless the technical idea as in the present application is added to the configuration of the flow control valve. It is useless.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art in the present invention, an electromagnetic pump is used as a means for obtaining a combustion amount adjusting device for a combustor having a return nozzle. And injects and burns it, and returns the surplus fuel oil amount between the return side of a return nozzle, which is a recirculation injection valve that returns the amount of fuel oil to the suction side of the electromagnetic pump, and the suction side of the electromagnetic pump. In the case where a flow rate adjusting valve for adjusting the injection amount from the return nozzle is interposed, an inlet for introducing the return fluid from the return nozzle, and an inlet for the electromagnetic pump by adjusting the introduced fluid. An orifice for returning, a needle valve slidably disposed in an axial direction in a fluid flow path for determining an opening position of the orifice with a valve seat and an opening degree per unit time; An electromagnetic plunger whose both ends are urged by a spring in conjunction with the valve and an opening position and an opening degree of the needle valve with respect to the orifice of the needle valve are variably adjusted to generate a magnetic force that determines the return flow rate. A flow control valve having an electromagnetic coil connected to a power supply capable of changing a cycle of the intermittent energizing pulse current and a conduction period during the cycle; an outlet of the flow control valve from the orifice and a suction side of the electromagnetic pump; Is characterized in that the passage in the joint that communicates with the hole has a substantially uniform diameter, a flat inner surface, and small pores that are relatively clear.

[0014]

According to the above construction of the present invention, the fuel oil is sucked and pressurized by the electromagnetic pump from the fuel oil tank via the suction side pipe, and is ejected from the return nozzle via the discharge side pipe. The injection amount, that is, the combustion amount, reaches the flow control valve from the return side of the return nozzle via the return pipe, and can be variably adjusted by adjusting the return amount here.

[0015] When there is no return amount from the nozzle at a predetermined pressure, the fuel oil pumped from the electromagnetic pump to the nozzle is injected at its entire flow rate and burns, which is the maximum combustion amount. When the combustion amount is to be sequentially reduced or increased again, the period of the intermittent pulse current to the electromagnetic coil of the electromagnetic amplitude type flow control valve (hereinafter simply referred to as the flow control valve) or mainly the conduction period during the cycle, that is, the duty ratio is varied. do it,
A needle valve articulated in conjunction with an electronic plunger that continues to reciprocate with amplitude by the spring and the intermittent magnetic force generated by energizing the electromagnetic coil is supported by a spring from both ends. The amount of combustion injected from the nozzle can be adjusted by increasing or decreasing the return amount determined by the degree of positional opening occupied in each cycle with the seat and the number of times of opening and closing per unit time.

The return flow rate from the outlet through the orifice of the flow control valve is adjusted by connecting a joint provided with the valve seat and the orifice and the outlet to a joint provided with a suction port and provided on the suction side of the body of the electromagnetic pump. Through the connected and connected passage, the fluid is collected by being joined to the fluid on the suction side of the pump.

The return fuel oil from the return nozzle has a large pressure and contains therein a gas such as a dissolved gas. When this fluid joins with the suction side fluid of the electromagnetic pump, when the oil level of the fuel oil tank is below the suction side, the suction side fluid has a negative pressure, so naturally the return fuel oil and its dissolved gas Vaporization becomes intense.

[0018] However, the fluid which has reached the valve seat of the orifice and is vaporized by the reciprocating vibration of the needle valve having a fine amplitude is such that the dissolved gas therein is finely divided together with the fuel oil and enters the passage in the joint. Has the effect of becoming Further, since the passage does not have a recess for accumulating and retaining air bubbles, there is no danger that the accumulated and expanded bubble mass will be released to cause air bubbles to be clogged with the suction or discharge valve of the electromagnetic pump. Since the pores have a uniform diameter and a flat inner surface and have a relatively narrow cross-sectional area, the dynamic pressure of the suction-side fluid including the return amount is reduced to increase the flow velocity, thereby increasing the flow rate of the bubbles. It is subdivided and quickly sucked into the pump body, and then jetted from the nozzle.

The finely divided gas that has entered the pump body is easily mixed therein because it is pressurized together with the liquid by the discharge plunger of the pump. Therefore, smoke due to incomplete deflagration combustion generated due to the variation of the fuel oil injection amount of the pump by the gas body described above with respect to the prior art,
There is no danger of generating harmful gas, vibration and noise.

FIG. 6A shows the state of the change in the discharge amount from the nozzle including the time when the combustion amount is adjusted. The description will be described later. Also, when the flow regulating valve that urges the intermittent pulse current to the electromagnetic coil is activated, the needle valve that has been in the closed stationary state in contact with the valve seat has a slightly lower top dead center, that is, in the direction of the lower annular magnetic pole together with the electromagnetic plunger. Since the valve moves and reciprocates with the amplitude therefrom, the needle valve does not always contact the valve seat during the operation of the flow regulating valve, so that there is no noise of contact between the needle valve and the valve seat, that is, generation of noise. However, there is no fear that the wear of these components is accelerated.

The above description of the operation is supplemented by the description of the embodiment of the present invention.

[0022]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
FIG. 1 is a configuration diagram showing a partial cross section of an embodiment of the present invention.

FIG. 2 shows an arrangement of a fuel system using the embodiment of the present invention shown in FIG. (1) and (2) are joints with the electromagnetic amplitude type flow control valve of one embodiment of the present invention, and constitute the main body of the flow control device, (3) is an electromagnetic pump, and (4) is a return nozzle. , (5) is a return fuel pipe, (6) is a filter provided on the fuel suction pipe side, (7) is a fuel oil tank, and (7 ') is a case where the oil level is higher than the suction side of the electromagnetic pump. A fuel oil tank, (8) is a suction side pipe, and (9) is a discharge side pipe.

FIG. 4 is an enlarged explanatory view of a main part of the electromagnetic amplitude type flow control valve (1). In the above figures, the electromagnetic amplitude type flow control valve (hereinafter simply referred to as flow control valve) (1) has an orifice (12), a valve seat (13), and an outlet (1
1 ′) is screwed into the joint body (28).

A guide (14) with a cone tip having a truncated conical portion is formed in the inner cavity of the joint (11) by a through hole (18) and a tip holder (17) wound with a filter (19) on the outside. It is tightly screwed into the truncated conical abutment portion.

On the base surface of the cone that the guide (14) with cone tip comes into contact with, a cut-line radial or radial oil guide is provided.
A plurality of radiation grooves (15), which may be turning grooves, are provided.

A needle valve (20) is fitted in the central longitudinal through-hole of the cone tip guide (14) so as to freely slide and reciprocate. The needle valve (20) has a needle-like tip, and a spring seat (23) provided at the other end abuts on the electromagnetic plunger (25) and has an auxiliary spring (2) between the tip presser (17).
2), and a return spring (33) is provided between the other end of the electromagnetic plunger (25) and a spring seat (32). The spring seat (23) and the electromagnetic plunger (2) in contact with the spring seat (23)
5) is supported by the auxiliary spring (22) and the return spring (33). The distal end portion of the needle of the needle valve (20) presses and closes the valve seat (13) of the orifice (12) at the time of rest without applying the intermittent pulse current to the flow regulating valve (1).

The adjustment rod (3) screwed into the body (38)
The tip of 4) is in contact with the spring receiving seat (23), and by turning the adjusting screw (34 ') to the right or left, each of the auxiliary spring (22) and the return spring (33) is turned. The electromagnetic plunger (25) and the needle valve (20) are displaced in the axial direction due to the sum of the deflection that is inversely proportional to the spring constant, and the needle valve (20) is pressed against the valve seat (13) or is pressed against the valve seat (13). The electromagnetic plunger (25) enables variable adjustment of the magnetic attraction force due to changes in the magnetic path such as the magnetic air gap.

In the electromagnetic plunger (25), a plunger case (29) having an annular magnetic path (30) at one end and an annular magnetic pole (31) at the other end is slidably reciprocally disposed. (29) has one end of a joint body (2
8), the other end is inserted into the main body (38).

Further, the plunger case (29) is inserted into the longitudinal axis hole of the electromagnetic coil (37) together with the annular magnetic path (30) and the annular magnetic pole (31) respectively fitted to both ends thereof. .

The outer box yoke (36) surrounding the electromagnetic coil (37) includes the electromagnetic coil (37) and the annular magnetic path (30) between the joint body (28) and the main body (38). A magnetic path is formed by sandwiching and fixing an annular magnetic pole (31), a magnetic washer, and the like.

An inflow joint (35) having an inflow port (35 ') is provided at a main part of the main body (38), and the suction side of the electromagnetic pump (3) to which the joint (11) is assembled from the inflow joint (35). The interior of the electromagnetic pump (3) is sealed by an O-ring or the like so as to keep the airtight from the outside until the joint (2) is reached.

The joint (2) is a joint on the suction side of the electromagnetic pump (3), and has a passage (10) communicating with the flow regulating valve (1). As shown in FIG. Are equal to each other, d ₁ = d ₂ = d _3, and a flat channel having no recess or step is formed.

The joint (2) is further provided with a threaded joint such as a nipple or the like. When a male screw and a female screw to be screwed with each other are formed with a recess which may form a bubble pool, or when the screw is screwed. There is a risk that the chips of the screws may be mixed into the fluid, and it is desirable to have a simple integrated structure as shown in the drawing as much as possible, or the joint (11) and the joint (2) may be integrated.

The electromagnetic pump (3) is a conventionally known electromagnetic plunger pump (Japanese Utility Model Publication No. 5-11353, Japanese Utility Model Publication No.
7-43102), although not shown, a suction valve,
Discharge valve, accumulator, relief valve or pressure reducing valve,
A pressure adjusting mechanism such as a pressure-increasing delay valve is provided for slow ignition combustion of the gun type oil burner.

Although the structure and operation are also omitted, the outline is that the magnetic force generated by energizing the electromagnetic coil for pump (95) with an intermittent pulse current by means such as half-wave rectification of the commercial AC current. The electromagnetic coil for the pump (9) is supported by the auxiliary spring (89) and the return spring (91).
The plunger case (9) provided in the through hole of the vertical axis center of (5)
3) and the cylinder (9) provided in the pump body (80).
8) and an electromagnetic plunger (90) which can be slidably reciprocated and fitted in the discharge plunger (9).
The pump action is performed by the volume change in the cylinder (98) of 7) in combination with the action of the suction valve and the discharge valve. Simultaneously with energization of the pump electromagnetic coil (95), the electromagnetic movable piece (85) is connected to the discharge port (81) by a magnetic force generated by energizing the electromagnetic valve coil (87) connected to the pump electromagnetic coil (95). The magnetic head (88) is attracted to the magnetic head (88) by a force that overcomes the repulsive force of the solenoid valve spring (86) urging the shut-off valve body (84) to close the shut-off valve seat (83). 8
Open 1). The fluid flowing from the suction port (100) as shown by the arrow a enters the pressure chamber (99) from the flow path of the pump body (not shown) via the suction valve, and further enters the plunger case (93) via the flow path from the discharge valve. And is discharged from the discharge port (81) as shown by an arrow c through an electromagnetic valve mechanism composed of an electromagnetic movable piece (85) and the like in the discharge joint (82). After that, the fuel oil reaches the nozzle (4), and the fuel oil sprayed therefrom is ignited and burns. Providing a fuel shut-off valve such as an electromagnetic valve on the discharge side of the electromagnetic pump (3) means that, when the electromagnetic pump is stopped, residual fuel in the pump causes residual fuel to be ejected from the nozzle into the furnace due to residual pressure inside the pump, or the oil in the fuel oil tank. When the surface is higher than the electromagnetic pump (3) as shown in FIG. 2 (7 '), it flows out of the nozzle when the pump is stopped and accumulates in the furnace to prevent accidents such as fire or explosion. .

When the fuel cutoff valve as shown in FIG. 1 is not built in the pump, it is necessary to attach a separate fuel cutoff valve such as a solenoid valve to the discharge pipe of the pump. The operation of the flow control device of the present invention including the flow control valve (1) and the joint (2) has already been described in the operation section of the present specification, and will not be described.

Driving for determining the period of the intermittent pulse current energizing the electromagnetic coil (37) of the electromagnetic amplitude type flow regulating valve (1), the conduction period (duty ratio) during the period, and making the flow rate of the fluid variable. The circuit of the power supply is also disclosed in, for example, Japanese Patent Publication No. 2-5145 proposed earlier by the applicant of the present application, and the description thereof will be omitted.

The nozzle described in Japanese Patent Publication No. 2-5145 regulates the spray angle, the pattern and the distribution of the spray to variably adjust the spray amount. However, there is a difference in the flow control valve for making the gas mixed in the liquid subdivide and flow out, but the above-mentioned electric control circuit may be the same or similar.

In this flow control valve, the valve seat (13) of the orifice (12) is closed by a needle valve (20) in principle when the valve is stopped, that is, when the electromagnetic coil (37) is turned off. However, in the case where the fuel tank may be slightly opened, when the oil level of the fuel oil tank (7) is lower than that of the pump when the pump is stopped, the return fuel pipe (from the return nozzle (4)) 5), flow control valve (1),
Discharge pipe (9) through joint (2), suction pipe (8)
Up to the oil tank (7) may be returned back to the oil tank (7), and each flow path may be emptied, which means that it takes time to remove air from each oil path when restarting. .

On the other hand, when the oil level is higher than the pump as in the fuel oil tank (7 '), there is a danger that the fuel oil will flow out of the return nozzle (4) into the furnace during the stop. Therefore, in such a case, the return fuel pipe (5) may be provided with an energization opening solenoid valve.

If an accumulator or a strainer with a built-in accumulator is interposed between the return side of the return nozzle (4) and the flow control valve (1), the pressure of the returned fuel oil is averaged and the injection pulsation from the nozzle is made. Can be further reduced, or contaminants such as trash that are present in the returned fuel oil can be removed.

The joint (11) of the flow regulating valve (1) is shown to be orthogonal to the flow path of the joint (2) on the pump suction side. There is no problem even if it flows in at an angle.

Next, the suction port (1) of the pump (3)
(11) Joint between suction side including flow rate control valve (00) and flow control valve (1)
The results of an experiment conducted to determine the shape and dimensions of the fluid passage (10) of the joint (2) connecting
(B), (c), (a), (b), (c) of FIG. 6 and FIG.

The arrow a indicates the direction of fuel oil from the fuel oil tank (7) to the suction port (100) via the suction pipe (8) and the filter (6), and the arrow c 'indicates the electromagnetic pump (3).
The direction of inflow to each is shown.

[0046] d ₁ is the side of the passage for flow of fluid to the electromagnetic pump (3) in (10), d ₂ is inlet to catch (2) (10
Passages (10) flowing from 0), d ₃ represents the respective diameter of the passage (10) flowing from the flow control valve (1) to the catch (2).

In this experiment, the fuel oil was JIS No. 1 white kerosene, the power supply of the electromagnetic pump (3) was a half-wave rectified current of a commercial AC power supply of 50 Hz, the voltage was 100 V, and the return nozzle was 1.3.
The results are shown in the following table at 5 GPH, an ambient temperature of 20 ° C., and a drive power source for the flow control valve at a direct current of 70 Hz.

[0048]

[Table 1] The arrangement configuration of the fuel oil system is as shown by the fuel oil tank (7) in FIG.

FIGS. 6A, 6B and 6C show the elapsed time t on the horizontal axis, 1/18 h on one scale (recording with a pen recorder at a speed of 18 cm per hour), and the vertical axis Q (L / h). The flow rate of the fuel oil injected from the return nozzle (4) is set to 70 Hz by applying a current to the flow rate regulating valve (1), and the ON time of the conduction period during the cycle is set to 0. T. 4, 5, 6, 7, 8, 10, 12m respectively
s (1/1000 seconds), and FIG. 6A shows the smallest change in the discharge pulsation.
This is of the shape and dimensions shown in FIG. Therefore, the experiment of the passage of the joint (2) of the present invention was carried out again in the same manner as in the experiment of FIG. 6A, and the result was completely the same.

The energizing current to the flow regulating valve (1) is
Hz is equivalent to 13 in the prior art shown in FIG.
Compared to the results of FIG. 7 tested at 3 Hz, the one shown in FIG. 1 of the present application should be compared with the one shown in FIG. Although there was an intention, the fact that the injection pulsation from the nozzle was much smaller than expected is evidence of the above-mentioned theory of the treatment of air bubbles in fuel oil. This state is also evident visually by the transparent synthetic resin joint (2).

As described above, since the electromagnetic pump (3) is normally driven with a half-wave rectified current of the commercial AC power supply, the frequency of the drive power supply for the flow regulating valve (1) is equal to the half-wave rectified current. A DC frequency of a rectangular wave which does not become a multiple of the frequency of 50 or 60 per second so as not to tune and resonate is selected.

In FIG. 8, the horizontal axis represents the conduction period on-time ms in the cycle of the frequency of the energizing current to the flow control valve (1) at the frequency Hz, and the vertical axis represents the injection amount Q ( (L / h) is a diagram showing flow rate characteristics.

In the figure, the value represented by the solid line is 70 Hz.
The one-dot chain line shows the on-time one flow rate characteristic at 110 Hz, and the one shown by the dotted line shows the on-time one flow rate characteristic at 130 Hz.

In this case, the adjusting screw (34 ') of the adjusting rod (34) of the flow rate adjusting valve (1) is turned to rotate the adjusting screw (34').
110Hz, 130
Hz, the adjustment screw (34 ') is rotated to change the sum of the flexures of the auxiliary spring (22) and the return spring (33) to change the combined repulsive force thereof.
Further, when the relative position between the electromagnetic plunger (25), the annular magnetic pole (31) and the electromagnetic coil (37) is changed, the strength of the magnetic force also slightly changes, and at the same time, the needle valve (20) changes the valve seat (13) of the orifice (12). 8) also changes, and the flow characteristics shown in each diagram in FIG. 8 also change. In the case of 110 Hz and 130 Hz, the shape characteristic similar to the diagram shown in the case of 70 Hz in FIG. 8 can be obtained by rotating and adjusting the adjusting screw (34 ') suitable for each case. Of course, the value of the flow rate that changes corresponding to each on-time is not the same.

The electromagnetic coil (3) of the flow control valve (1)
The intermittent pulse current energized to 7) is caused by a rise in the temperature of the coil itself over a long period of time when the current is supplied, absorption of radiant heat from the combustor, changes in the ambient temperature and the temperature of the fuel oil, and the like. This causes a change in the current value due to a change in the electrical resistance value of the magnetic field, and this may also change the magnetic attraction force and impair the function of the flow control valve (1). Therefore, it is desirable that the energizing current power supply be provided with a constant current device (see Japanese Patent Application Laid-Open No. 2-57816).

[0056]

As described above, the apparatus for adjusting the combustion amount of a combustor provided with a return nozzle having the structure according to the present invention has the following functions and reasons described in the description of the embodiments. Effects can be obtained. (A) The amount of combustion of a combustor provided with a return nozzle such as a gun-type oil burner, that is, the amount of fuel oil injection or spray discharge from the nozzle is determined by a single nozzle, and the return flow from the fuel oil return side. By the electromagnetic amplitude type flow control valve,
When energizing the intermittent pulse current to the electromagnetic coil of the flow regulating valve, the cycle and mainly the conduction period during the cycle are varied to adjust the return flow rate so that the combustion amount is continuously or stepwise. In addition to facilitating electrical control, the pulsation of injection from the nozzle is extremely low, and noise, vibration and harmful exhaust gas due to deflagration or incomplete combustion, standing flame, etc. resulting from air-fuel ratio imbalance due to the pulsation. Prevent dangerous pollution such as (B) A gas such as a dissolved gas contained in excess fuel oil returned from the return nozzle to the suction side of the pump via the electromagnetic amplitude type flow control valve generates the intermittent pulse current of the needle valve in the flow control valve. Due to the magnetic force and the repulsive force of the spring pressing from both directions, the crushing action accompanying the opening which repeats the reciprocating motion constantly with amplitude between the orifice valve seats,
Since it is finely divided with the liquid, uniformly mixed, and flows into the suction side of the pump from the outlet, the pump is overwhelming in the market as a fuel pump for a burner such as a heating or water heater for home use or small business. In the case of the electromagnetic pump widely used in the above, the damage described in the above item (a) due to the clogging of the bubble and the fluctuation of the discharge pressure flow rate as described in the section of the operation can be further prevented. (C) The passage connecting the outlet of the flow control valve and the suction-side flow passage of the electromagnetic pump is made of a relatively small cross-sectional area having a substantially uniform diameter and a flat inner surface. There are no recesses that accumulate and grow by accumulating the bubbles contained therein, and the bubbles are fragmented and pass at an increased flow rate,
It is sucked into a pump, where it is pressurized and then discharged. Particularly when an electromagnetic pump is used, the effect described in the above item (b) is further increased to smooth the pulsation in the spray state and to prevent the pulsation fluctuation. It is useful for. (D) When the combustion is stopped, the adjustment screw is adjusted so that the needle valve of the flow control valve closes the valve seat of the orifice at the outlet, thereby causing a fire or incomplete combustion due to leakage of the fuel oil. Accidents such as generation of harmful gas due to the above can be prevented. And it is economical because there is no need to provide an electromagnetic valve for turning off and on the return pipe on the return pipe side of the return nozzle.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a partial cross section of an embodiment of a combustion amount adjusting device for a combustor having a return nozzle according to the present invention.

FIG. 2 is a configuration diagram showing a connection arrangement of a fuel system of a combustor using the embodiment of the present invention shown in FIG. 1;

3 (a), 3 (b) and 3 (c) are used for experiments for determining the shape and size of a joint having a flow communication valve and a passage communicating with the suction side of an electromagnetic pump according to the present invention. It is each sectional drawing of the done joint.

FIG. 4 is an enlarged sectional view of a main part of the flow control valve according to the present invention.

FIG. 5 is a cross-sectional view of a conventional flow control valve.

FIG. 6 is a graph showing the relationship between the intermittent pulse current applied to the flow control valve and the amount of fuel injected from the return nozzle when each of the joints shown in FIGS. 3A, 3B and 3C of the present invention is used. It is a fluctuation characteristic diagram.

FIG. 7 is a characteristic diagram of a temporal variation characteristic of the intermittent pulse current for energizing the flow control valve of the fuel injection amount when the conventional technique shown in FIG. 5 is used.

FIG. 8 is a characteristic diagram of the amount of injection from the return nozzle with respect to the period of the energizing intermittent pulse current to the flow regulating valve and the conduction period during the period, and the variation with time thereof, by the apparatus according to the present invention.

[Explanation of symbols]

 1. 1. Electromagnetic amplitude type flow control valve Joint 3. Electromagnetic pump 4. Return nozzle 5. Return fuel piping 6. Filter 7.7 '. Fuel oil tank 8. 8. Inlet side piping Discharge side piping 10. Passage 11. Joint 12. Orifice 13. Valve seat 20. Needle valve

Claims (1)

(57) [Claims] 1. A return side of a return nozzle which is a recirculation injection valve for feeding fuel oil under pressure by an electromagnetic pump to inject and burn the fuel oil and return an excess fuel oil amount to a suction side of the electromagnetic pump, and suction of the electromagnetic pump. A flow regulating valve for adjusting the injection amount from the return nozzle by adjusting the return amount between the return nozzle and the return nozzle.
An inlet (35 ') for introducing the return fluid from the pump, an orifice (12) for adjusting the introduced fluid and returning it to the suction side of the electromagnetic pump (3), and a valve seat (13) for the orifice (12). A) a needle valve (20) slidably disposed in an axial direction in a fluid flow path for determining an opening position and an opening degree per unit time with the needle valve; Plunger (25) urged by springs (22, 33) and orifice (12) of needle valve (20)
An electromagnetic coil connected to a power supply capable of varying the period of the intermittently energizing pulse current and the conduction period during the period for variably adjusting the opening position with respect to the opening degree and the opening degree such as the opening frequency to generate the magnetic force that determines the return flow rate A flow control valve (1) having a flow control valve (37), and a joint for communicating an outlet (11 ') of the flow control valve (1) from the orifice (12) and a suction side of the electromagnetic pump (3). (2) Adjusting the combustion amount of a combustor equipped with a return nozzle, characterized in that the inner passage (10) has pores having a substantially uniform diameter and a flat inner surface and a relatively small cross-sectional area. apparatus.