JPH01305219A - Liquid fuel combustion device - Google Patents

Abstract

PURPOSE:To vary the combustion rate through a single burner head, by a method wherein, through regulation of the amount of fuel returned from the bypass nozzle of a liquid fuel combustion device used for a kerosene hot water boiler, the amount of sprayed fuel is varied. CONSTITUTION:Fuel fed to a bypass nozzle 26 from a fuel pump 21 is sprayed by means of the bypass nozzle 26 for combustion. A part of fuel oil is returned to a return flow passage 31 having a solenoid valve 32 and an orifice 33. A control part 34 drives the fuel pump 21, opens and closes the solenoid valve 32 to vary the spray amount, and varies the combustion rate. Since the orifice 33 is molded integrally with a piping connecting member 35 through which an outlet piping part 32A on the downstream side of fuel oil is connected to a piping 31A of the return flow passage 31, mounting of an orifice 33A to the return flow passage 31 is facilitated, resulting in reduction of a cost.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a liquid fuel combustion device used as a heat source for oil hot water boilers, etc., and particularly to an orifice used in the liquid fuel combustion device.

BACKGROUND OF THE INVENTION In recent years, liquid fuel combustion devices have adopted a method of varying the amount of combustion.

The conventional liquid fuel combustion apparatus will be explained below based on the drawings. FIG. 6 is a block diagram of a conventional liquid fuel combustion device. Fuel oil a supplied from an oil tank (not shown) passes through an oil strainer 1, is pressurized by a fuel pump 2, passes through one feed channel 3A, is fixed to a nozzle holder 4A, and is sent to the nine nozzles A'5A. The fuel is also sent from the fuel pump 2 through the other sending channel 3B to the nozzle 115B fixed to the nozzle holder 4B via the solenoid valve 6. These fuel oils a are sprayed from nozzles 1v5A, 5B, ignited by an igniter such as a high-pressure plug (not shown), and driven by a blower 9 consisting of a motor 7 and a fan 8 to nozzles 1v5A, 5B.
5B is mixed with the empty 'jKb sent to the burner heads IOA and IOB where burner heads 10A and 1 are installed.
Burns in front of 0B. The control unit 11 controls the fuel pump 2. The motor 7 and solenoid valve 6 of the blower 9 are controlled, and by opening and closing the solenoid valve 6, the fuel oil a supplied to the nozzle Iv5B is cut off or released, and the amount of combustion is varied by varying the amount of injection '4g. are doing.

Problems to be Solved by the Invention However, in the conventional configuration, two nozzles /115A and 5B are provided, and a burner head 10A is provided for each of the nozzles /L'5A and 5B.

10B, and if you try to control the combustion amount even more finely, you will need a large number of burner heads, so the structure of the burner becomes complicated, and the structure of the part where the burner is attached to the heat exchanger becomes complicated. It's hot. The pressure of the fuel pump 2 differs depending on whether both NOS 1v5A and 5B are used and when only one is used, and furthermore, the pressure of the fuel pump 2 is different when using only one burner head 10A and 10B and when both are used. In the case where the combustion performance of the burner changes due to the influence of each other's flames and the different e[ of the air flows blown out from the burner heads 10A and 10B that are not burning, there is a problem that the combustion performance of the burner changes, and the air-fuel ratio changes due to temperature changes. There is a problem that the combustion performance of the burner deteriorates due to changes in fc.

The present invention solves the above-mentioned problems, and provides a defined means for solving the problems by reducing the number of burner heads and simplifying the burner configuration. ~, a fuel pump that supplies fully pressurized fuel oil to the bypass nozzle y, and a solenoid valve and an orifice connected in series in a flow path that returns the fuel oil from the return port of the bypass nozzle to the inlet side of the fuel pump. The orifice is integrally formed at the tip of the piping connection member. Further, in the present invention, the orifice is made of a thin plate, divided into two parts in the direction of the return flow path and at the rear, and is sandwiched between fixed pipe connecting members and fixed integrally. Furthermore, in the present invention, the inner diameter is tapered toward the tip, the orifice is formed at the tip, and the orifice molded member is divided into two parts in the direction of the return flow path, and is sandwiched between the piping connection members and fixed integrally. It's a thing.

Operation With the above configuration, the fuel oil supplied under pressure from the fuel pump is sprayed from the bypass nozzle, and a portion of the fuel oil passes through the return port of the bypass nozzle and returns to the inlet side of the fuel pump through the return flow path. It will be done.

Therefore, by driving the fuel pump and opening and closing the solenoid valve installed in the return flow path together with the orifice, the amount of fuel oil sprayed from the bypass nozzle is varied by adjusting the amount of return oil, and the total amount of combustion is adjusted. can. At this time, since only one nozzle μ is required, only one burner head is required, which simplifies the configuration of the burner and the part that attaches the burner to the heat exchanger, and compared to the case where there are multiple nozzles and multiple burner heads. This stabilizes the fuel pump pressure and eliminates the effects of flame and air flow between the burners, resulting in stable burner combustion performance. Furthermore, by integrally forming the orifice at the tip of the pipe connection member, the orifice can be easily installed in the flow path, and the number of parts that make up the liquid fuel combustion system can be reduced, reducing costs. can be measured. Furthermore, by dividing the orifice or the molded member formed at the tip of the orifice into two parts and sandwiching them between fixed pipe connecting members, the orifice can be easily assembled and the compatibility with orifices of different diameters and thicknesses is improved. Furthermore, by installing a thicker orifice, it is possible to change the amount of fuel oil passing through the orifice according to temperature changes, and the fuel oil spray t'(il
- Automatically variable and always maintains the optimum air-fuel ratio,
Combustion performance can be improved.

Example An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram of a liquid fuel combustion apparatus showing an embodiment of the present invention. In FIG. 1, reference numeral 21 indicates an oil supply path 23 from an oil tank (not shown) through an oil μ leveler 22.
The fuel oil C sent through the feed channel 24 is pressurized.
Bypass nozzle fixed to nozzle holder 25 through
It is a fuel pump that supplies fuel to L/26, and fuel pump 21
The fuel oil C sent to the bypass nozzle 1v26 is atomized at the bypass nozzle/L'26, ignited by an igniter such as a high-pressure plug (not shown), and then
I/26 is installed, and the air is mixed with combustion air Xd sent from a blower 30 consisting of a motor 28 and a fan 29 to the nine burner heads I, and is combusted in front of the burner head n. Also, friend fuel oil C sent to Pybus Nozzle 1v26
A part of the return passage 3 returns the oil μ repeller 221C from the return port of the pibus nozzle/v26 to the inlet side of the fuel pump 21.
It is returned to 1. A solenoid valve 32 and an orifice 33 are provided in the return flow path 31 and are connected in series. Then, the control unit 34 drives the fuel pump 21, opens and closes the solenoid valve 32 to vary the spray amount of fuel oil C sprayed from the bypass nozzle/L/26, and controls the motor 281r- of the blower 30 according to the spray amount. The amount of air is controlled to vary, and the combustion 'jk is varied.

In this way, since the combustion amount can be controlled with one bypass nozzle/L/26 and one burner head 27f, the configuration of the burner and the configuration of the part where the burner is attached to the heat exchanger can be simplified. Compared to the case where there are a plurality of burner heads, there is no influence of each other's flames or influence of the total airflow, and the pressure of the fuel pump 21 is stabilized, making it possible to stabilize the combustion performance of the burner.

FIG. 2 shows a sectional view of a pipe connecting member provided with an orifice 33 at its tip. The piping connection member 35 shown in FIG.
1 piping 31At - is a piping member to be connected to the solenoid valve 3
A filter 37 is provided at the connecting portion 36 of the return flow path 31, and the connecting portion 38 of the return flow path 31 is shaped like a bar, with an orifice di at the tip.
, an orifice 33A having an effective thickness tl is provided.

In this way, by integrally forming the orifice 33A in the piping connection #j35, it becomes extremely easy to attach the orifice 33A to the return passage 31, and the number of components of the liquid fuel combustion device can be reduced, resulting in cost reduction. All needles can be used. Also, orifice diameter d of orifice 33A
By changing lf, the return flow rate of fuel oil C passing through the orifice 33A'e can be changed, and the bypass nozzle, /
The amount of fuel oil C sprayed from 1/26 can be varied.

FIG. 3 shows a sectional view of a pipe connecting member provided inside the orifice 33. The piping connection member 39 shown in FIG.
Similar to the piping connection member 35 shown in the figure, it is a piping member that connects the outlet piping part 32A of the solenoid valve 32 and the piping 31A of the return flow path 31, and is a piping member that is divided into two parts in the front and back in the return path direction.
It consists of an upstream member 42 having a connecting portion 41 for the return passage 40 and the solenoid valve 32, and a downstream member 44 having a connecting portion 43 for the return passage 31, and between them there is a thin plate orifice diameter and an orifice 33B having an effective thickness tl. Insert it and hit 0 ring 6! It is configured as follows.

With such a configuration, the orifice 33B can be easily replaced, and by changing the orifice diameter d of the orifice 33B, the return flow of the fuel C passing through the orifice 33B can be improved. k can be changed, and the amount of fuel oil C sprayed from the Tokui Pass nozzle/L'26 can be changed.

Furthermore, as shown in FIG. 5 (aJ), even if the motor 280 rotation speed of the blower 30 is constant, the amount of air e (indicated by the two-dot chain line) supplied to the burner head 27 decreases as the temperature rises. However, the low injection W amount f (indicated by the solid line) when the solenoid valve 32 is open is almost constant even when the temperature rises, and the air-fuel ratio deteriorates and combustion performance worsens, so the ideal spray It is necessary to change the spray amount of fuel oil C, that is, the flow rate of fuel oil C passing through the orifice 338 ft, so as to obtain the amount g (shown by the broken line) 1r. To change the flow f of C.

It is preferable to change the rotation speed of the fuel pump 21 or to increase the effective thickness tx of the orifice 33B.

Effective thickness t of orifice 33B! If it becomes thicker, fuel oil C
When the temperature rises, the kinematic viscosity decreases, and the flow rate of the fuel oil C passing through the orifice 33B increases, so that the injection mi can be lowered by the rise in temperature.

In Fig. 5 fb), the solenoid valve 32 is closed, the rotation speed of the fuel pump 21 is reduced by the control unit 34 according to the temperature change, and the high spray amount at time t is shown by the two-point m line, and the solenoid valve 32 is opened. year,
Effective thickness t that is less affected by the kinematic viscosity of fuel oil C! The solid line indicates the low spray amount 31 when using the thin orifice 33B'fr, and the broken line indicates the low spray amount j++ when using the thick orifice 33B with effective thickness i.

By replacing the orifices 33B with different effective thicknesses tx in this way, especially by replacing with a thicker orifice 33B having an effective thickness tx, it is possible to obtain an ideal spray amount g in response to changes in the air amount C due to temperature changes. is possible,
Even if there are temperature changes, combustion can be performed at an excellent air-fuel ratio, improving combustion performance.

Note that instead of the thin plate orifice 33B shown in FIG. 3, an orifice 33 with an orifice diameter ds and an effective thickness [3] shown in FIG.
The orifice forming member 46 may be sandwiched between pipe connecting members divided into two parts in the front and rear directions of the return flow path.

In addition, in the tree embodiment shown in FIG.
An oil leveler 22 is used to release the air that is sucked in from the tip of the oil filter 26 and passes through the entire return flow path 31 into the atmosphere, but instead of the oil leveler 22, an automatic air venting device is provided in the middle of the return flow path 31. You can. Blower 30
Control the amount of air from the rotation speed of the motor 28? Although this is done by controlling, it can also be done by providing a damper in the passage of all the air d and varying the damper opening degree.

Effects of the Invention As described above, according to the present invention, the amount of fuel oil sprayed from the bypass nozzle is controlled by controlling the flow rate of the fuel oil returned from the return port of the bypass nozzle by opening and closing the solenoid valve. The combustion amount can be controlled by this spray amount. Furthermore, one bypass nozzle requires Wt h"2, and only one burner head is required, which simplifies the configuration of the burner and the configuration for attaching the burner to the heat exchanger. Compared to a case where there are two or more heads, there is no influence of flame or air flow from each other, and the pressure of the fuel pump is stabilized, making it possible to stabilize the combustion performance of the burner.3. By integrally forming the connecting member at the tip, it is possible to reduce the number of parts constituting the liquid fuel combustion bag, thereby reducing costs.Furthermore, the orifice or the molded member formed at the orifice metal tip can be reduced. By sandwiching the orifice between the two divided piping connecting members, it is possible to improve compatibility with orifices of different diameters and thicknesses. . In response to changes in the amount of air supplied to the burner head, the amount of fuel oil passing through the orifice (t) is varied in response to changes in temperature.

The amount of fuel oil sprayed from the bypass nozzle can be changed in response to changes in the amount of air due to temperature changes,
Is it optimal even with temperature changes? It can burn at the same fuel ratio and improve combustion performance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a liquid fuel combustion device showing an embodiment of the present invention, FIGS. 2 and 3 are sectional views of a piping connection member provided with an orifice of the same liquid fuel combustion device, and FIG. 5E9 (at and fbl are characteristic diagrams of the air amount and fuel oil spray amount due to temperature changes of the liquid fuel combustion device, respectively; Fig. 6 is a configuration diagram of a conventional liquid fuel combustion device. 21...Fuel pump %26...Bypass nozzle, 3
1... Return flow path, 32... Solenoid valve, 33.33A,
33B, 33C... Orifice % 35.39... Piping connection member, 4G... Orifice molding member, C...
Fuel oil, dl* dx +dx...orifice diameter, b
*b l ts... Effective thickness (of orifice). Agent Yoshihiro Moriki Figure 1 21 441 pieces in length 2? 〉F' 32
Electric stone a push 26 Haiha 0 Sunonuru J3-1
+1 fiss 3t-4srJ+L, road c y
q, i+rm Fig. 2 Fig. 3 j2 ・Orifice diameter tz - 1 piece / 9 pieces Fig. 4 U Fig. 1 False (°C) (I X product/iCOC)

Claims (1)

[Claims] 1. A bypass nozzle that sprays fuel oil, a fuel pump that pressurizes and supplies fuel oil to the bypass nozzle, and supplies fuel oil from the return port of the bypass nozzle to the inlet side of the fuel pump. A liquid fuel combustion device comprising a solenoid valve and an orifice connected in series in a return flow path, the orifice being integrally formed at the tip of a piping connection member. 2. A bypass nozzle that sprays fuel oil, a fuel pump that pressurizes and supplies fuel oil to the bypass nozzle, and a flow path that returns fuel oil from the return port of the bypass nozzle to the inlet side of the fuel pump, which are connected in series. A liquid fuel combustion device comprising a solenoid valve and an orifice connected to each other, the orifice being a thin plate, sandwiched between pipe connecting members divided into two parts in the front and back in the direction of the return flow path, and fixed integrally. 3. A bypass nozzle that sprays fuel oil, a fuel pump that pressurizes and supplies fuel oil to the bypass nozzle, and a flow path that returns fuel oil from the return port of the bypass nozzle to the inlet side of the fuel pump, which are connected in series. Consisting of a connected solenoid valve and orifice, the inner diameter tapers toward the tip,
A liquid fuel combustion device in which an orifice molded member having the orifice formed at its tip is inserted and integrally fixed between piping connecting members divided into two parts in the front and back of the flow path direction.