JPS58182024A - High load and high tdr combustion device - Google Patents

Abstract

PURPOSE:To enlarge a stable combustion zone in the combustion device which is adapted to perform a high load combustion by supplying air forcedly to a flame so as to minimize the length of the flame by providing an air supply part having air holes in the peripheral wall in the flame forming direction of a flame hole and also a means for varying the opening area of the flame hole. CONSTITUTION:An air supply part 11 having a number of air holes 10 is provided on the righthand and lefthand of a flame hole 9, and a flame hole opening area varying plate 13 is provided within the slit of the flame hole 9 slidably therethrough. In this instance, the plate 13 is dimensioned so as to define some space on the righthand and lefthand thereof within the slit. In the operation, as the combustion rate changes from the maximum to the minimum, the flame hole opening area varying plate 13 is ascended orderly within the flame hole by a motor 16, thereby changing the flame from a jellyfish-shaped secondary flame to a double-topped secondary flame. Thus, by maintaining the mixed gas injection velocity at a substantially constant level, such a combustion is obtained that the combustion speed, distribution speed of unreacted gas and air injection speed are all substantially balanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a fan or the like to forcefully supply air to a flame in a combustion machine such as a water heater or space heater to shorten the flame and achieve high-load combustion. In addition to downsizing the combustion equipment,
From the standpoint of ease of use, this article is about a combustion device that widens the range of twist 411+4''- from the conventional false to below zero, widens the stable combustion range at that time, and makes it easier to control the air-fuel ratio. As a high-load combustion device, there is one shown in FIG. An air supply plate 3 having air holes 2 on the peripheral surface in the flame formation direction in the jetting direction of the mixed gas of gas and air from the flame holes 1.
has been established. The flame hole 1 is connected to a fuel supply [14] by a fuel supply pipe 5.

- The mechanical vent 2 communicates with the air supply port 6 via an air chamber, 8 is a spark plug. In this configuration, a mixture of air and gas supplied from the fuel supply pipe 5 as shown by the arrow is ejected from the flame hole 1, and at the same time, air forcibly sent by a fan or the like from the air supply pipe 216 as shown by the arrow Nono [1<, the air is ejected from the air hole 2 at an angle so that it hits the air-fuel mixture 11, and is ignited by the spark plug 8 to form a flame, but the flame does not cross the flame hole, but from the air hole 2. The air and air mixture ejected from the air vents diffuse and a flame is formed along the air flow lines of the air vents 2. 1 Hashi 1 can be realized. As shown in an example in Fig. 5, the stable combustion region is A.

If high-load combustion is achieved at point A in the quadrupled hatched region of curve B, the flow rate of the mixed gas decreases as shown in curve C as the combustion rate decreases, and the amount of combustion decreases. At the same time, the air flow velocity in the air hole 2 is also decreased, and the air flow rate is gradually moved within the stable combustion area.
n Ratio (TDR).

However, in reality, due to variations in the fans that supply air (voltage fluctuations, mass production variations, etc.) and variations in the fuel mixture, the result is a change that resembles a quadruple dotted line along curve C. The intersection entrance or ノ is TD
This indicates that the mixed gas flow rate cannot be changed between 1 and 0.4 inches, that is, the TDR is 15.Since flame hole 1 and air hole 2 are constant, the amount of combustion is reduced. As a result, the flow rate of the mixed gas from flame hole 1 decreases, and the air flow rate must also decrease accordingly.This is because curve A generates yellow flame and the flame extends, causing the combustion gas to flow into the heat exchanger, etc. on the flow side. Co/CO
The line where 2 increases indicates that the minimum amount of air required for one combustion decreases as the flow rate of the mixed gas decreases. One-way line B shows the line where the flame blows out, the flame front is disturbed, unreacted Go is emitted, and the amount of Co/CO2 increases - again, the maximum amount of air that forms a combustion flame that does not generate CO is the mixed gas. This shows that as the flow velocity decreases, the air flow velocity also decreases. FIG. 5 shows the case where the air-fuel ratio of the mixed gas is kept constant, and it goes without saying that the curve curve B also changes when the air-fuel ratio of the mixed gas is changed. Therefore, the fifth
Decreasing the mixed gas flow rate in the diagram will indicate a reduction in the burnup meter, or TDR.

Therefore, in the case of the conventional configuration shown in FIG. 1, when TDR is used, a fuel control valve that reduces the flow velocity of the mixed gas, that is, the amount of fuel supplied, and an air amount control device that changes the air amount, such as a fan rotation speed control. In addition to interlocking the two, a distribution control device for controlling the amount of air sent to the flame hole 1 and the air hole 2 is required. Furthermore, if we take into account the variations in the fuel control valve, the air flow control device, the air flow distribution control device, and the variation in their control circuits, we will end up with a change like the dotted line surrounded by curve C.
This has the disadvantage that the R range is narrow. It requires three control devices: a fuel control valve, an air amount control device, and an air amount distribution control device, and their control circuits are complicated, and the TDR range will be limited unless efforts are made to improve the accuracy of each. It also has the disadvantage that it does not spread.

The present invention eliminates and reduces the drawbacks listed in -1-, simplifies the control device, and improves the precision of various variations. This is the purpose.

In order to achieve this object, the present invention provides a method for forcibly supplying air to a flame to turn it into a field flame and achieve high-load combustion.
An air supply section having air holes is provided on the peripheral wall of the flame hole in the flame formation direction, and a device for varying the opening area of the flame hole is provided.

With this configuration, by reducing the opening area of the flame hole as the combustion amount decreases, the jetting speed of the air-fuel mixture from the flame hole is kept almost constant, and stable combustion is achieved even when the fluctuation amount of the air flow rate is large. Air amount control by TDR becomes unnecessary, and the control accuracy is also improved.

An embodiment of the present invention will be described below using the perspective sectional view of FIG. An air supply section 11 having a large number of air holes 1° is provided on the left and right sides of the flame hole 9, and a joining chamber 12 is formed at the F side of the flame hole 9 to 4". , the flame hole area variable plate 13 that slides inside the slit hole of the flame hole 9 is provided in a size that creates a gap on the left and right sides of the slit hole, and an air supply chamber 14 is provided around the mixing chamber 12 between the air hole 10 A motor 16 is provided on the outside of the box 15 to operate the variable flame hole area plate 12 up and down inside the flame hole 9. As shown in the figure, the variable flame hole area plate 13 is connected to the motor 16 and the sliding shaft 1.
7, and the OIJ song 8 prevents mixing of air and mixed gas in the mixture chamber 13 and air chamber 14. 8The flame hole area variable plate 13 is made of metal or ceramic with low thermal expansion. Figure 3.

The operation will be explained with reference to FIG. Figure 3 shows the case where the combustion amount is maximum, and the flame hole area variable plate 13 is the motor 16 with respect to the flame hole 9.
The air-fuel mixture is lowered downward by the slit 1 of the flame hole 9 and exhibits a velocity distribution as shown by the dotted line throughout the entire area, and the flame follows the airflow distribution shown by the arrow due to the primary flame shown by the dashed line and the diffusion of unreacted gas. A jellyfish-like secondary flame is formed. FIG. 4 takes TDR and shows the case where the combustion amount is minimum, and the flame hole area variable plate 13 is pushed up inside the slit flame hole 9 by the motor 16 as shown in the figure, and the slit of the flame hole 9 is moved upward as shown in the figure. The slits in the gaps at both ends become the main flame holes. Although there is a gap in which the flame hole area variable plate 13 slides not only in the longitudinal direction of the slit but also in the much shorter direction, the main flame hole is only the gap at both ends of the flame hole in the longitudinal direction shown in the figure, and in this case, the mixed gas The flow velocity distribution follows the main flame hole and protrudes from both ends of the flame hole, as shown by the dotted line. In this case, the flame is a primary flame shown by a dotted line 1j, and a secondary flame with two peaks is formed by diffusion of unreacted gas, following the air flow shown by arrows. In this case, since the amount of combustion is small, only the air holes in the first stage of the air holes 10 are effective for combustion, and the other air holes are supplied as surplus air.

Therefore, by sequentially raising the flame hole area variable plate 13 through the flame hole by the motor 16 as the combustion amount changes from the maximum combustion amount to the minimum combustion amount, the flame changes from a jellyfish-shaped secondary flame to a secondary flame with two peaks. Change. The reason why the tip of the plate 13 with a variable flame hole area of n holes is made into a chevron shape is to form a flame in the flame hole 9 so that even during combustion, only the tip of the chevron is affected by the temperature.

In this way, as the combustion amount is reduced, the chevron-shaped flame hole area variable plate 13 is raised inside the slit-shaped flame hole 9 to reduce the flame hole area and keep the jetting speed of the mixed gas almost constant, thereby increasing the combustion rate. Because it is possible to perform combustion while keeping the speed, diffusion rate of unreacted gas, and air injection rate almost balanced, the combustion range can be controlled as shown by the constant line of the mixed gas flow rate, as shown in Figure 5. In most cases, it is sufficient to control the variation in the mixed gas flow rate and air flow rate using the dotted lines along the line. That is, as shown in the figure, since the mixed gas flow rate can be controlled at a constant rate of 1 m/s, the air flow rate changes from the point of intersection with curve A to the point of intersection with curve B, that is, 2 to 5 m/s i. It is not recommended to use it in a wide area with a very stable combustion range because it allows for variations in the air flow rate.The control of the air flow on the air side can be very rough, and in some cases, the control on the air side may not be necessary. The ratio of the air flow velocity to the mixed gas flow velocity in curves A and B is constant and the same as in the conventional case, which is 2.59, - times, but in the conventional case, such a change is necessary in curve C, and TD
By simply setting R to 5 as shown in the diagram, the air flow rate will be 1 to 2°6.
If it has to be kept to m/s, it will be difficult, and in order to achieve the TDR of Toshi, it will be 0.2 m/s = 0.5 m/i +
Even if the 0 point is set to 2rr1/B, the air flow rate must be controlled to a minimum, but with this configuration, the air flow rate only needs to be in the range of 2 to 5 I. However, it has the effect of allowing a very rough air amount range. Therefore, as in the past, the TDR limit is at its limit, and it is possible to achieve only <'Ao. This can be achieved by reducing the gap formed by the flame hole area variable plate 13 and the flame hole 9. Since the air flow range is wide, only two control devices are required: a fuel control valve and an air flow distribution control device, eliminating the need for a conventional air flow control device, and even with the addition of a control circuit, air-fuel ratio control only requires three parts Furthermore, since the combustion range is wide and it can be used in places where large fluctuations in air flow rate are acceptable, it has the effect of simplifying the control parts and eliminating the need for accuracy.

Furthermore, with this configuration, as the TDR is taken, the air holes in the - stage of the air holes 10 escape as bypass air, so when used in a water heater, etc., the heat exchange efficiency is stabilized, and when the TDR is taken as in the conventional case, condensed water is removed. It also has the effect that the durability of the heat exchanger does not become a problem. By making the tip of the variable flame hole area plate 13 into a chevron shape, the thermal influence of the variable flame hole area plate 13 is reduced, the durability is improved, and the influence of expansion and contraction is reduced.

In the embodiment, a Bunsen flame is used to form a primary flame, but it can be spread and applied using a diffusion flame.

According to the high-quality load height TI)R combustion apparatus of the present invention as described below, an air supply section having air holes is provided on the peripheral wall of the flame hole in the flame formation direction, and the opening area of the flame hole is By reducing the amount, the ejection flow velocity of the mixed gas can be kept constant, the air flow velocity fluctuation value is large, and combustion can be performed in a wide stable combustion region, so the range of variation in the absolute value of the air amount is widened. Since the control device does not require an air amount control device, the control accuracy can be rough, and the mixed gas flow rate is set so that it can be used in a wide range of stable combustion even when TDR is used. By providing a variable flame hole area plate so that the flame hole area is variable and the mixed gas flow rate is constant, an effect can be obtained in which the TDR can be reduced from the conventional mechanism.

The figure is a perspective view of a high load height TDR combustion device according to an embodiment of the present invention, and FIG. 3 is a sectional view showing the flame state at maximum combustion.
FIG. 4 is a sectional view showing the flame state at the time of minimum combustion, and FIG. 5 is a characteristic diagram showing the stable combustion region.

9...Flame hole, 1Q...Air hole, 11.
... Air supply section, 13 ... Flame hole area variable plate.

Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 f.

Fig. 3 f ( Fig. 4 0 Fig. 5 'e ''l-% baking tQ , 'CO/C (,, <o, oo
O Habe Note Urubu Suburbs 4rt〈Evening □

Claims (1)

[Claims] Air is forcibly supplied to the flame to shorten the flame, and an air supply section having an air hole is provided on the peripheral wall in the direction of flame formation of the flame hole.
A high-quality load height TD in which a device for varying the opening area of the flame hole is provided so that the opening area decreases as the combustion amount decreases.
R combustion device.