JP3891531B2 - Gas combustion heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to means for heating an object to be heated by burning gaseous fuel such as gas, etc., and dramatically improves the heat transfer rate to the endothermic surface, improving heat utilization efficiency and reducing air pollution with a relatively simple configuration. It is about the combustion heating technology which aims at prevention.
[0002]
[Prior art]
Conventionally, this type of burner and heating device generally uses a so-called Bunsen burner that inhales 40 to 70% of primary air and burns it completely in contact with the surrounding secondary air when it burns at the flame outlet of the burner. The body was also heated by directly applying the heat from the flame directly to the endothermic surface. Also, an all-primary air premix burner that mixes all the air necessary for combustion with fuel gas and supplies it to the flame outlet of the burner for combustion, and a blast burner and primary air that are forced to burn at high loads by a blower There are many types of burners such as the red fire type that do not use the heat. However, the hot air from the combustion flames of these burners naturally comes into direct contact with the heat absorption part to heat the object to be heated. Furthermore, in some cooking appliances, there is also an apparatus in which heat of combustion exhaust is blown to food by a fan to improve heat transferability. In addition, there has also appeared an apparatus for spraying combustion high-temperature exhaust at a high speed for local heating and heating only that part.
[0003]
In these known burners and heating methods, various problems have occurred because it is difficult to improve the heat utilization efficiency, the apparatus is complicated and difficult to use, and there are many problems in cost. . In particular, because high-temperature flames and exhaust are in direct contact with the surrounding air, it is not easy to reduce harmful nitrogen oxides.
[0004]
On the other hand, means has been developed to reduce the volume of the combustion chamber and to perform high-load combustion and to devise a heat exchanger to obtain high efficiency, but there is an adverse effect on the burner etc. due to the condensed water of the exhaust, and Bunsen In recent years, a technique for reducing the production of nitrogen oxides by burning so-called light and dark combustion in a burner has been developed. However, many problems of the prior art have not been completely solved.
[0005]
[Problems to be solved by the invention]
The present invention solves these drawbacks in the conventional combustion heating method according to the prior art, and solves these drawbacks. In particular, in the configuration of a relatively simple endothermic surface, the number of general natural direct heating methods. An object of the present invention is to provide a combustion heating apparatus that can be used for general purposes by obtaining a heat transfer effect more than doubled to increase the thermal efficiency and suppressing generation of nitrogen oxides generated during combustion.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the invention of claim 1 is a premixing method in which almost all combustion air necessary for gas combustion is mixed with fuel gas, and this mixed gas is supplied to a burner using a blower and burned. In the forced combustion type burner, the burner's flame outlet has a number of small holes or narrow grooves or a combination of small holes and narrow grooves, and hot exhaust gas from the flame burned in the flame port is connected to the burner downstream of the burner. In addition , the combustion heating part is configured in such a way that it is ejected in a direction almost perpendicular to the main endothermic surface of the object to be heated from a plurality of outlets that are opened in the exhaust body provided separately and collides with the endothermic surface. The blower capacity, burner heating value and outlet area are set so that the flow velocity of combustion exhaust from the jet outlet is 5 m / sec or more during combustion at the rated maximum heat value, and the combustion exhaust from the burner is ejected. airtight space portion leading to the spout While the granulation, in a configuration in which ejection member is positioned above the burner through the space portion, exhaust gas ejected from the ejection port condensed water that generates Ri by that is cooled by the heat absorbing surface, the burner as a means to prevent dripping on the flame opening corresponds to perpendicular projection area of the flame port portion in the configuration, or jetting body providing a shielding plate serving as a receiving water in the space located in the middle of the flame hole and jetting body The present invention relates to a gas combustion heating apparatus characterized in that the portion is configured such that no jet port is eliminated or the hole area of each jet port is made small enough to prevent water from dripping due to surface tension .
[0007]
According to the second aspect of the present invention, the fuel gas is supplied to the mixing portion of the combustion air via an electrically controlled gas proportional solenoid valve and mixed with almost all the air necessary for combustion, and this mixed gas is burned and burned. It is sent to the burner by a blower having the wind pressure and air volume necessary for the ejection of exhaust gas, but a distribution plate for uniform combustion is provided in the passage of the air-fuel mixture leading to the burner's flame outlet, an ignition device for the burner, misfire A detector and an air-fuel ratio control sensor are installed at a position relatively close to the burner flame opening in an airtight space composed of a burner and a jet, and the ignition and combustion control are communicated with these devices and detectors. A gas combustion heating apparatus according to claim 1, further comprising an electronic control device that operates as described above.
[0008]
According to a third aspect of the present invention, the object to be heated is a liquid such as water, and the combustion exhaust gas penetrating through a part of the water storage tank and a cylindrical notch that houses the ejector in the lower part of the cylindrical water storage tank A sensor that detects the heating temperature of liquid such as water by arranging a jet, a burner and a flame outlet, a blower, and a control device so that it can be applied to the configuration of a water can heating device provided with an upward discharge passage. 2. A device having a device for controlling the amount of combustion heating by a signal, and housing the components in a main body case so as to form a single unit as a hot water storage type water heater. This relates to the gas combustion heating apparatus shown in item 2.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In the gas combustion heating apparatus of the present invention, first, a gas serving as fuel is supplied to a portion where it is mixed with combustion air through a gas shut-off valve, a gas control valve, and a supply pressure regulator that normally control the gas supply amount. Hereinafter, the embodiment will be described. In the embodiment shown in FIG. 1, the gas control valve and the supply pressure regulator are denoted by reference numeral 1, and the mixing unit is denoted by reference numeral 2. Since the apparatus of the present invention is a combustion system using a premixed forced combustion burner, the mixed gas of air and gas produced in the mixing section 2 is pumped to the burner 5 through the supply pipe 4 by the blower 3. Since the form of the burner needs to form a uniform flame, a chamber chamber having an appropriate volume is provided on the upstream side of the flame port 6 which is one of the elements of the burner structure, and as shown in claim 2 therein. It is preferable to insert the distribution plates 7, 7 ', 8.
[0010]
The mixed gas of fuel gas and air reaches a flame port 6 having a plate-like form in which a plurality of small holes or narrow grooves or a combination of small holes and narrow grooves, and is ignited by an igniter 9 (or an ignition flame). The mixed gas is ignited to form a flame. It is necessary to control the air / fuel mixture ratio, that is, the air-fuel ratio and the jetting speed of the supply gas mixture so that the flame form is a relatively short flame and does not backfire. It is desirable to control so that it becomes.
[0011]
The temperature of the flame is 1000 ° C. or higher, and the exhaust temperature in the internal space 11 of the exhaust ejector 10 is slightly lower than this, and the gas is ejected from a number of outlets 12 that open to the ejector. At this time, the hole area of each jet outlet is designed to be a relatively small area so that the jet speed of exhaust becomes high. The jet exhaust is configured in this part so that it is ejected in a direction almost perpendicular to the main endothermic surface 13 of the object to be heated and collides with the endothermic surface. However, the shape of the ejector and the endothermic surface are not necessarily limited. Since it is not necessary to make it flat, the jet direction of the jet exhaust is not always right at a microscopic level. However, the concept of the present invention is to obtain a heat transfer coefficient several times to several tens of times that of a heating method using a normal burner due to the destruction of the heat insulating boundary film due to the collision of the high temperature exhaust with the heat absorbing surface. Therefore, it is necessary to collide in a direction close to a right angle macroscopically.
[0012]
The distance between the ejector and the endothermic surface is preferably close to the exhaust so that it can be released to the outside, but it is also related to the ejection speed, the amount of ejection, and the shape of the external passage of the exhaust. The value should be designed. On the other hand, as for the ejection speed, a certain speed is required on the premise of the destruction of the heat insulating boundary film on the endothermic surface. In order to exert the effect of the present invention, 5 m / The capacity of the blower, the amount of heat generated by the burner, the area of the jet outlet, and other related elements should be designed so as to be at least 2 seconds.
[0013]
The relationship between the burner 5 and the jet body 10 is an airtight structure in order to first maintain the jet pressure of the exhaust from the jet body and prevent the combustion exhaust from coming into contact with air and generating harmful nitrogen oxides. In addition, consideration should be given to prevent the radiant heat from the ejector from hitting the burner's flame mouth strongly in order to prevent the flashback phenomenon and maintain the durability of the flame mouth by overheating the flame mouth. The ejector internal space 11 for separating the surface of the ejector 10 facing the burner at an appropriate distance should have an appropriate space volume.
[0014]
Also, if the jet port of the jet body as in Example is located at the top side of the burner port of the burner, exhaust from the condenser effect of water vapor in the exhaust gas that is produced by cooling in contact with the heat absorbing surface A water droplet drops on the flame outlet 6 and adversely affects the flame outlet and the burner. For the purpose of preventing this, a shielding plate serving as a water receiver for condensed water is provided between the flame outlet and the jet body, or at least the flame. Although the portion of the jet body, which corresponds to the vertical direction of the projected area of the mouth should be configured to eliminate the spout, when spout is required for unavoidable portions thereof, the burner from even spout during stopping combustion In order to prevent the condensed water from dripping onto the surface of the flame outlet, the shape of each of the small-area jet outlets and the shape of the peripheral part of the jet outlet should be taken into consideration. In addition, the figure of an Example shows only the case of the form which eliminated the jet nozzle in the part of the ejection body.
[0015]
In the present invention, the combustion is performed stably and completely, and the combustion exhaust is configured to collide with the heat absorption surface with a predetermined ejection speed and the shape of the ejection exhaust, that is, a needle shape as much as possible. Since this is an extremely important technique, the performance of the blower and the fuel supply are controlled quickly and precisely using the electronic control unit 14 as shown in claim 2, and the misfire detector 15 and the detection sensor 16 for air-fuel ratio control are used. Can be provided at a position relatively close to the flame outlet of the burner in an airtight space constituted by the burner and the ejector, and the electronic control device can be provided with a predetermined control function based on signals from these detection devices. This is necessary when the inventive device is applied to relatively high-end products.
[0016]
FIG. 1 of the embodiment shows a general configuration when the gas combustion heating device of the present invention is applied to a hot water storage type water heater. In this case, an object to be heated is a liquid such as water, and a cylindrical water storage A cylindrical notch 18 that houses the jetting body 10 and a discharge passage 19 upward of the exhaust that penetrates a part of the water storage tank are provided in the lower part of the tank 17 so that the liquid in the water storage tank 17 is effectively heated. The combustion heating device of the present invention is arranged in the lower part so that it can be made.
[0017]
In this embodiment, the function of controlling the amount of combustion heat is controlled by signals from the sensor 20 for detecting the temperature of the liquid in the water storage tank and the water level detection sensor 21, a blower excluding a part of the piping, and electronic control All the elements constituting the hot-water storage water heater such as the apparatus and the combustion section are housed in a main body case (not shown) so as to be a single unit.
[0018]
In FIG. 1 showing one embodiment, 22 is an overheat prevention sensor, and 23 is a baffle plate provided in the exhaust discharge passage 19, which has a slight effect on increasing the heat efficiency by reducing the exhaust temperature.
Further, 24 is a water supply pipe to the water storage tank, 25 is a hot water discharge pipe, 26 is an overpressure safety device, and 27 is a flame flashback detector.
[0019]
Embodiments of the present invention are not limited to those shown in the above examples, and various embodiments are conceivable within the scope of the concept of the present invention. For example, the object to be heated may not be a liquid, and the shape of the ejector can be conical, square tube, dome, bell shaped, etc., and the surface of the ejector need not be flat, for example, corrugated Various application forms such as a staircase shape are possible.
[0020]
【The invention's effect】
The present invention is implemented with the configuration described above, and has the following effects.
[0021]
High-temperature exhaust due to burner combustion collides with the heat-absorbing surface of the object to be heated at high speed from a large number of outlets of the ejector. Efficiency is obtained. Therefore, high-efficiency heating is possible with a simple structure at a relatively low cost, which is economically excellent and can reduce carbon dioxide emissions.
[0022]
In the premixed combustion method using all primary air, secondary air is not used, and the burner combustion flame passes through the airtight chamber composed of the ejector and the burner part, from the outlet of the ejector that is lower than the flame temperature. Due to the jetting configuration, there is no contact with air in the middle, and cooling to a certain degree and combustion is completed in a short time with a short flame, so that generation of harmful nitrogen oxides can be greatly suppressed.
[0023]
Since the gas combustion heating apparatus of the present invention can be applied to almost all kinds of objects to be heated, the range of application to various uses is wide.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view showing an embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gas control valve and supply pressure regulator 2 Mixing part 3 Blower 4 Supply pipe 5 Burner 6 Flame outlet 7,7 ', 8 Distribution board 9 Igniter 10 Ejector 12 Ejector 13 Heat absorption surface 14 Electronic controller 17 Water storage tank

Claims (3)

In a premixed forced combustion burner in which almost all of the combustion air necessary for gas combustion is mixed with fuel gas and this mixed gas is supplied to the burner using a blower and burned, the burner's flame outlet has a number of small holes. or a shape combining narrow grooves or small holes and narrow grooves, the hot exhaust from the flame and burned in the flame port portion, from the ejection port to multiple open to ejection of provided separately from the exhaust from the burner downstream of the burner The combustion heating part is configured in such a way that it is ejected in a direction almost perpendicular to the main endothermic surface of the object to be heated and collides with the endothermic surface, and the flow rate of the combustion exhaust from the outlet is the rated maximum calorific value so as to be more than 5 m / sec at the time of combustion by the ability of the blower, with setting the amount of heat generated and spout area of the burner, the space portion combustion exhaust from the burner reaches the ejection port of the ejection member in airtight, jet Body through the space In the structure located above the over Na, as a means to prevent the exhaust gas ejected from the ejection port condensed water that generates Ri by to be cooled by the heat absorption surface, dropped into the flame port portion of the burner, burner port and jet body intermediate the receiving water space situated shielding plate provided construction of, or individual jets or eliminate jets in a portion corresponding to perpendicular projection area of the flame port portion at the ejection member A gas combustion heating apparatus characterized in that the hole area of the gas is made small enough to prevent water from dripping due to surface tension . Fuel gas is supplied to the combustion air mixing section via an electrically controlled gas proportional solenoid valve and mixed with almost all the air necessary for combustion, and this mixed gas has the wind pressure required for combustion and ejection of combustion exhaust. Is sent to the burner by a blower having an air volume, but a distribution plate for uniform combustion is provided in the passage of the air-fuel mixture leading to the burner's flame opening, and an ignition device, a misfire detector, and an air-fuel ratio control to the burner Electronic control device which is arranged in a position relatively close to a burner flame opening in an airtight space comprising a burner and a jet body, and controls ignition and combustion in communication with these devices and detectors The gas combustion heating apparatus according to claim 1, comprising: The object to be heated is a liquid such as water, and a cylindrical notch for storing the ejector is provided at the bottom of the cylindrical water storage tank, and a discharge passage is provided above the combustion exhaust that passes through a part of the water storage tank. In order to be applicable to the configuration of a water can heating device, a jet, a burner and a flame outlet, a blower, and a control device are arranged, and the combustion heating amount is determined by a sensor signal that detects the heating temperature of a liquid such as water. Gas combustion heating according to claim 1 or 2, characterized in that it has a control device and is housed in a main body case so that its constituent elements are combined into a single unit as a hot water storage type water heater. apparatus.

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