JPH0596741U - Combustion device - Google Patents

Abstract

(57) [Abstract] [Purpose] Accelerate the agitation and mixing of the exhaust gas coming out of the combustion chamber to the chimney 7, and accurately detect the concentration of the gas to be detected in the exhaust gas by the detection sensor 11 provided at the base side of the chimney 7. . [Structure] A plurality of swirl vanes 14 are arranged in a tangential direction of an imaginary circumference of a central portion in an exhaust port cover 12 serving as an exhaust port of a combustion chamber, and fixed to the exhaust port cover 12, and an exhaust gas mixer 13 is provided. Constitute. When the exhaust gas generated in the combustion chamber enters the chimney from the exhaust outlet, the swirl vanes 14 are added to provide swirl force,
The exhaust gas uniformly stirred and mixed is guided to the chimney 7.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a combustion device such as a water heater or a bath cooker in which a chimney is connected to an exhaust outlet of a combustion chamber.

[0002]

[Prior Art]

 FIG. 9 shows a schematic structure of a water heater generally known as a combustion device. In the figure, a burner 2 is arranged on the lower side of the combustion chamber 1, and a fan 3 for supply and exhaust is provided on the lower side of the burner 2. A heat exchanger 4 is provided on the upper side of the combustion chamber 1, and a chimney 7 is connected to the exhaust outlet 5 side of the combustion chamber 1 via a connecting tube 6.

In this type of water heater, the water supplied through the water supply pipe 8 is heated by the combustion heat of the burner 2 as it passes through the heat exchanger 4, and becomes hot water. The water is guided to a desired place such as a kitchen or bathroom via the.

Usually, in this kind of water heater, the concentration of carbon monoxide gas or carbon dioxide gas in the exhaust gas generated by burner combustion in the combustion chamber 1 is detected by a detection sensor 11 provided in the chimney 7. However, it is equipped with safety devices such as stopping combustion when the detected concentration exceeds the reference concentration.

When detecting the concentration of carbon monoxide gas or carbon dioxide gas in the exhaust gas passing through the chimney 7, the exhaust gas is discharged while being stirred as it passes through the chimney 7. Therefore, stirring is not performed at the outlet of the chimney 7. Sufficiently performed, the concentration of the detected gas such as carbon monoxide gas or carbon dioxide gas can be accurately detected. However, if the detection sensor 11 is provided on the exit side of the chimney 7, there arises a problem that the concentration of the gas to be detected cannot be detected when the seam of the chimney 7 falls off in the middle. If it is installed on the outlet side, the distance from the water heater main body that receives the signal from the detection sensor 11 and performs safety control becomes extremely long, and the wiring work between the detection sensor 11 and the water heater main body becomes complicated. Therefore, the detection sensor 11 is usually attached to the base side of the chimney 7.

[0006]

[Problems to be solved by the device]

 However, if the detection sensor 11 is attached to the base side of the chimney 7 to detect the gas concentration, the exhaust gas entering the chimney 7 from the combustion chamber 1 is not sufficiently agitated yet, so the exhaust gas entering the chimney 7 is exhausted. Since the concentration of the gas to be detected in the gas becomes non-uniform, there arises a problem that the concentration of the gas to be detected cannot be accurately detected by the method of detecting at a fixed point using one detection sensor 11. In particular, as shown in FIG. 9, the burner 2 is divided into two parts 2a and 2b, and during single-sided combustion in which only the burner 2a is burned, a large variation occurs in the distribution of the gas to be detected on the exhaust outlet 5 side, and the chimney inevitably occurs. There is a large variation in the distribution of the detected gas in the exhaust gas that enters 7.

FIG. 12 and FIG. 13 show the results of measuring the dispersion state of the distribution of the detected gas on the exhaust outlet side of the combustion chamber 1 and the root side of the chimney 7. In this measurement, as shown in FIG. 10 and FIG. 11, the inside of the exhaust port cover 12 of the combustion chamber 1 is divided at the points indicated by the 11 cross marks A to K, and the detected sensor is moved to each divided position. The concentration of carbon monoxide gas at each position was measured, and similarly, at the root side of the chimney 7, the inside of the chimney with a diameter of 60 mm was divided along the diametrical direction at a plurality of dot positions, and detection sensors were provided at each divided position. Is measured to measure the concentration distribution of carbon monoxide gas in the stack 7. Fig. 12 shows the measurement results of carbon monoxide gas at the respective positions A to K in the exhaust port cover 12. Of these, (a) of FIG. 12 shows the measurement results when only the burner 2a is burned on one side, and (b) of the same figure shows the measurement results of the double-sided combustion state where the burners 2a, 2b are burned.

In this experiment, both when the water heater was burned in a normal state and when the combustion state was intentionally deteriorated by blocking a part of the exit area of the chimney 7 to increase the generation of carbon monoxide gas, The measurement was carried out under the condition, and the results are shown together. During abnormal combustion, the amount of carbon monoxide gas generated becomes extremely large, and the distribution of carbon monoxide gas varies for both single-sided and double-sided combustion. There are large deviations and variations. Fig. 14 shows the distribution of carbon monoxide gas concentration in the exhaust gas passing through the root of the stack 7 when the water heater is abnormally burned, and the result of measuring the distribution of the carbon monoxide gas at the positions of the division points. The variation in the carbon gas concentration is also in a variation state corresponding to the distribution in the exhaust port cover 12. The variation state of the detected gas in the exhaust port cover 12 and at the root side of the chimney 7 is similar to that of the carbon monoxide gas in the case of carbon dioxide gas.

In FIG. 14, the horizontal axis indicates the carbon monoxide gas concentration measured at the exit side of the chimney 7, and the vertical axis indicates the carbon monoxide gas concentration by a fixed point method using a CO sensor provided on the base side of the chimney 7. When the output voltage of the CO sensor at the specified time is taken, the ratio of blocking the outlet of the chimney 7 is changed to change the concentration of carbon monoxide gas contained in the exhaust gas. The concentration and the output of the CO sensor at the root of the chimney are changed. The relationship with the voltage (detection density) is obtained. Since the carbon monoxide gas concentration on the horizontal axis of this graph is the concentration detected on the exit side of the chimney 7, the mixed state of the carbon monoxide gas is uniform and the generated concentration of carbon monoxide gas is positive. It shows exactly. As can be seen from the measurement results, there is a difference between the maximum output value and the minimum output value of the CO sensor in single-sided combustion and double-sided combustion, respectively. Also has a large variation. For example, when the output voltage of the CO sensor is detected as a level of 1360 mV, the detected concentration of carbon monoxide gas is calculated as a value of about 1100 to 3000 ppm, and there is a variation of about 1900 ppm between the maximum and minimum, There is a problem that the concentration of the gas to be detected in the exhaust gas on the base side of the chimney 7 cannot be accurately detected.

Of course, it is possible to accelerate the stirring and mixing of the exhaust gas by disposing a plate or the like that imparts passage resistance on the exhaust outlet 5 side of the combustion chamber 1, but if this is the case, the exhaust gas There arises a problem that the passage resistance increases and the combustion state in the combustion chamber 1 deteriorates. In order to avoid the deterioration of the combustion state, the rotational speed of the fan 3 may be increased by the amount of increase in the passage resistance, but if this is done, a new problem arises in that the rotational noise of the fan 3 increases.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to increase passage resistance even when a detection sensor is installed at the base side of a chimney and measurement is performed by a fixed point method. It is an object of the present invention to provide a combustion device capable of accurately detecting the concentration of the gas to be detected in the exhaust gas without the need.

[0012]

[Means for Solving the Problems]

 The present invention is configured as follows to achieve the above object. That is, the present invention is a combustion device of a type in which exhaust gas generated by combustion in a combustion chamber is discharged to the outside through a chimney from an exhaust outlet of the combustion chamber, and the exhaust gas is swirled at the exhaust outlet portion of the combustion chamber. The exhaust gas mixer is equipped with swirl vanes that mix and lead to the chimney.

[0013]

[Action]

 In the present invention having the above structure, the exhaust gas generated by the combustion in the combustion chamber is swirled by the swirl blades of the exhaust gas mixer when entering the chimney from the exhaust outlet of the combustion chamber, and the swirling and mixing of the exhaust gas is performed by this swirling. Is sufficiently performed to enter the chimney, and the uniform concentration of the detected gas in the exhaust gas is detected by the detection sensor.

[0014]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. In the following description of each embodiment, the same parts as those in the conventional example are designated by the same reference numerals, and the duplicated description will be omitted. FIG. 1 shows the configuration of essential parts of a first embodiment of a combustion apparatus according to the present invention. The combustion apparatus of this embodiment is intended for the water heater of the type shown in FIG. 9, and a characteristic of this embodiment is that the exhaust gas is swirled and stirred at the exhaust outlet of the combustion chamber 1. The exhaust gas mixer 13 for mixing is provided, and other configurations are the same as those of the conventional example.

The exhaust gas mixer 13 of this embodiment is characterized in that a plurality of swirl vanes 14 are provided in the exhaust port cover 12. In FIG. 1, the connecting cylinder 6 is connected and fixed to the central opening edge portion 9 of the top surface 15 of the exhaust port cover 12, and the root side of the chimney 7 is connected to the connecting cylinder 6. A sensor mounting hole 16 is formed in the joint surface between the base of the chimney 7 and the connecting tube 6, and a detection sensor 11 for detecting a gas to be detected such as carbon monoxide gas or carbon dioxide gas is fixed to the sensor mounting hole 16. Then, the gas detection surface of the detection sensor 11 is projected into the chimney 7.

Inside the exhaust port cover 12, a plurality of swirl vanes 14 are oriented in a direction that is tangential to an imaginary circumferential surface that is substantially the same as the chimney 7 (in this embodiment, the tangential direction is used, but the A plurality of swirl vanes 14 are arranged, and the outer end 14a side of each swirl vane 14 is the inner surface of the side wall 17 of the exhaust port cover 12. The exhaust gas mixer 13 is formed by being fixed by welding or other appropriate means.

As described above, by providing the swirl vanes 14 inside the exhaust port cover 12 to configure the exhaust gas mixer 13, the exhaust gas generated by the combustion of the burner 2 has climbed up to the exhaust outlet 5. Since it sometimes flows along the swirl vanes 14, as shown in FIG. 2, swirl force is applied before entering the chimney 7 to swirl, and as a result, mixing and agitation of exhaust gas is promoted and uniformized. The exhaust gas stirred in the stack enters the chimney 7, and the detected gas concentration is detected by the detection sensor 11. Therefore, even if burner combustion is performed in either single-sided or double-sided combustion state, the detected gas in the exhaust gas is detected. It is possible to accurately detect the gas concentration.

FIG. 3 shows the result of detecting the carbon monoxide gas concentration in the exhaust gas by the detected sensor 11 under the same conditions as in FIG. As can be seen from this detection result, in this example, the variation between the maximum detection value and the minimum detection value in both single-sided combustion and double-sided combustion is extremely small, and the variation between single-sided combustion and double-sided combustion is also small. It has been demonstrated that the concentration of the gas to be detected is detected in a well-stirred state. According to this measurement result, for example, when the detection output of the detection sensor 11 is 1120 mV, the variation in the concentration of carbon monoxide gas is approximately 270 ppm, which is much smaller than the variation of 1900 ppm in the case of FIG. It can be seen that accuracy detection is obtained.

Further, since the swirl vane 14 functions as a guide for giving a swirl force to the exhaust gas, and swirls the exhaust gas smoothly along the swirl vane 14, the swirl vane 14 is provided. The generated exhaust gas passage resistance is also very small, which is almost the same as the resistance when the swirl vanes 14 are not provided, and does not adversely affect the combustion in the combustion chamber 1.

FIG. 4 shows a second embodiment of the present invention. In the second embodiment, a closed inner lid 20 is fixedly arranged at the lower part of the inner end surface 18 of the swirl blade 14, and the other structure is the same as that of the first embodiment. The closed inner lid 20 may have a short columnar shape as shown in FIG. 5 (a), or a bowl-like shape having a downward opening as shown in FIG. 5 (b). It may be a conical shape that is convex downward as shown in FIG.

By providing the closed inner lid 20, the exhaust gas rising from the burner 2 (2a, 2b) side is prevented from rising directly to the chimney 7 along the inner end space portion 19 of the swirl vane 14, Since all the exhaust gas is given a swirling force along the swirl vanes 14 and enters the chimney 7 while being agitated and mixed, the agitation and mixing is promoted more than in the first embodiment, and the accurate target with less variation is obtained. The detection gas concentration can be detected. In this case, since the exhaust gas rising in the central portion of the combustion chamber 1 hits the closed inner lid 20, the passage resistance of the exhaust gas becomes larger than that of the first embodiment, but this passage resistance increase is small. Therefore, the combustion in the combustion chamber 1 is not adversely affected, and a good combustion state can be maintained.

FIG. 6 shows a third embodiment of the present invention. In the third embodiment, the upper end of the stirring cylinder 22 is connected and fixed to the edge portion of the passage opening 21 to the top surface 15 of the exhaust port cover 12, and a plurality of swirl vanes 14 are provided inside the stirring cylinder 22. The exhaust gas mixer 13 is formed by cutting and raising the structure, and the other structure is the same as that of the first embodiment.

Also in this third embodiment, when the exhaust gas generated in the combustion chamber 1 reaches the exhaust outlet 5, it enters the inside of the stirring tube 22 through the cut-out 23 of the cut-and-raised portion of the stirring tube 22, As shown in FIG. 7, by swirling along the swirl vanes 14, swirling force is applied and the mixture is uniformly stirred and mixed. As a result, the concentration of the gas to be detected is detected at the fixed point of the sensor 11 as in each of the above-described embodiments. By this, it becomes possible to detect accurately. In this embodiment, as shown in FIG. 8, the lower end surface of the stirring cylinder 22 can be closed by the closing inner lid 20, and when the lower end surface is closed, the lower part of the stirring cylinder 22 is lowered. All of the exhaust gas rising from the above flows into the outer peripheral side of the stirring cylinder 22 and flows along the swirl vane 14 from the cut end 23, so that the stirring and mixing of the exhaust gas can be further promoted.

The present invention is not limited to the above-mentioned embodiments, and various embodiments can be adopted. For example, in each of the above embodiments, the hot water supply device was described as the combustion device, but the present invention is applied to various combustion devices such as bath heaters and heaters that use gas or oil as fuel.

The detection sensor 11 is a CO sensor or CO₂Not limited to sensors, O ₂ A sensor or the like may be used as long as it can detect the combustion state by detecting the gas contained in the exhaust gas, and may be a sensor for detecting another gas type.

[0026]

[Effect of the device]

 According to the present invention, an exhaust gas mixer having a swirl vane is provided at the exhaust outlet of the combustion chamber, so that when the exhaust gas generated in the combustion chamber exits the chimney, the swirl force of the exhaust gas mixer causes swirl force. Therefore, the concentration of the gas to be detected can be accurately detected even if the detection sensor provided on the base side of the chimney detects it by the fixed point method. Is possible.

Further, since the exhaust gas smoothly flows along the swirl vanes, the passage resistance does not increase due to the provision of the exhaust gas mixer, and therefore, good combustion is achieved without increasing the rotation speed of the fan. It is very convenient because it can ensure driving.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of the essential parts of a first embodiment of a combustion apparatus according to the present invention.

FIG. 2 is an explanatory diagram of a swirling and mixing state of exhaust gas in the same example.

FIG. 3 is a graph of measurement experimental data of carbon monoxide gas in the same example.

FIG. 4 is an exploded perspective view of the essential parts of a second embodiment of the present invention.

FIG. 5 is an explanatory view of a form example of a closed inner lid in the same embodiment.

FIG. 6 is an exploded perspective view of the essential parts of a third embodiment of the present invention.

FIG. 7 is an explanatory diagram of a swirling stirring state of exhaust gas in the example.

FIG. 8 is an explanatory view of a mode in which the lower end surface of the stirring cylinder is closed in the same example.

FIG. 9 is a schematic structural diagram of a water heater generally known as a combustion device.

FIG. 10 is an explanatory diagram of data sampling positions when a measurement experiment of the concentration of a detected gas is performed inside the exhaust port cover and inside the chimney using the water heater of the conventional example.

11 is a plan view of FIG. 10.

FIG. 12 is a graph showing the results of measuring the distribution state of carbon monoxide gas at the exhaust outlet of the combustion chamber using the conventional water heater.

[Fig. 13] Fig. 13 is a graph showing the results of measurement of the distribution state of the carbon monoxide gas concentration on the root side of the chimney using the conventional water heater.

FIG. 14 is a graph of measurement data of carbon monoxide gas concentration detected by a CO sensor provided on the root side of a chimney of a water heater in a conventional example.

[Explanation of symbols]

 1 Combustion chamber 2, 2a, 2b Burner 5 Exhaust outlet 7 Chimney 11 Detection sensor 12 Exhaust port cover 13 Exhaust gas mixer 14 Swirling blade

Claims (1)

[Scope of utility model registration request] 1. A combustion apparatus of a type in which exhaust gas generated by combustion in a combustion chamber is discharged to the outside from an exhaust outlet of the combustion chamber through a chimney. An exhaust gas mixer having swirl vanes leading to a chimney is provided.