JPH0412322Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Field of industrial application) This invention uses gas as fuel, does not require air supply from a blower except during startup, and incorporates a pulse combustion device that has advantages such as high-load combustion and high thermal efficiency. Regarding pulse combustion boilers. (Prior Art) In recent years, boilers incorporating gas-fired pulse combustion devices, which lead to energy savings and high thermal efficiency, have been developed. FIG. 5 is a schematic vertical cross-sectional view of a conventional gas-fired pulse combustion boiler, which consists of a boiler body 17 in which canned water is stored, and a steam chamber 18 in the boiler body 17. It is composed of an exchanger 19, a gas-fired pulse combustion device 20 whose combustion chamber C is immersed in canned water in the boiler body 17, and a heat transfer tube 21 whose one end is immersed in canned water and communicates with the combustion chamber C. There is. Further, the first-stage pulse combustion device 20 includes a combustion chamber body 22 including a combustion chamber C, a mixing chamber body 23 connected to the front wall of the combustion chamber body 22, and a mixing chamber D communicating with the combustion chamber C. Ignition electrode 24 arranged in mixing chamber D
, an air flap valve 25 that intermittently supplies air to the mixing chamber D, a gas flap valve 26 that intermittently supplies gas to the mixing chamber D, and an ignition blower connected to the air flap valve 25. It consists of 27 mag.
City gas, propane gas, methane gas, etc. are used as fuel gas. Thus, the gas supplied to the mixing chamber D and the blower 2
7 is mixed with the air forcibly blown in in the mixing chamber D, and when the mixture is ignited by the ignition electrode 24, the first combustion occurs. The combustion gas at this time is discharged from the heat exchanger tube 21 due to the pressure generated by combustion, and gives heat to the canned water. During this time, gas and air do not flow into the mixing chamber D because the flap valves 25 and 26 are closed. Then, due to the exhaust inertia of the combustion gas, the combustion chamber C
When the pressure becomes negative, the flap valves 25 and 26 open, and the gas and air are naturally drawn into the mixing chamber D, where they are re-ignited by the residual flame and combust. Thereafter, the same cycle as above is repeated 10 to 100 times per second. However, in the boiler, the shape of the combustion chamber C is spherical or cylindrical, which is suitable for pulse combustion, and the heat transfer tube 21 is also a straight tube or a straight tube with a circular cross section to increase the inertia during exhaust. Since a coiled type with a large curvature was used, there was a problem that the canned water capacity increased. As a result, problems such as a longer startup time and difficulty in following sudden load fluctuations occurred. (Problems to be solved by the invention) The present invention was devised to solve the above problems, and its purpose is to provide a gas-fired pulse combustion boiler that can reduce the capacity of canned water. be. (Means for solving the problem) The present invention consists of a pulse combustion device 1 that uses gas as fuel.
A plurality of units consisting of a combination of a heat exchanger tube 2 and a heat exchanger tube 2 communicated with the combustion chamber A are arranged in parallel, and the combustion chamber A and the heat exchanger tube 2 of each unit are immersed in canned water in the boiler body 3. In a gas-fired pulse combustion boiler, the cross-sectional shapes of the combustion chamber A and the heat transfer tubes 2 are formed into a rectangular shape, and the heat transfer tubes 2 are bent multiple times in a canned water to form each heat transfer tube 2.
Exhaust sound attenuator 1 whose end is located below the front of the boiler body 3 and opens upward to the rear of the boiler body 3.
6, and furthermore, each pulse combustion device 1 is entirely surrounded by a cover 14, and communicated with an intake noise attenuator 15 provided at the lower part of the exhaust noise attenuator 16 below the boiler main body 3. This is the basic structure of the idea. (Operation) When the gas supplied to the mixing chamber and the air supplied are mixed in the mixing chamber and ignited by the ignition electrode, initial combustion occurs. The combustion gas at this time is discharged from the heat exchanger tube due to the pressure generated by combustion, and gives heat to the canned water. During this time, gas and air are prevented from entering the mixing chamber. Then, when the combustion chamber becomes negative pressure due to the exhaust inertia of the combustion gas, the gas and air are naturally drawn into the mixing chamber, and are re-ignited by the residual flame and combust. Thereafter, the same cycle as above is repeated. (Example) Hereinafter, an example of the present invention will be described in detail based on the drawings. FIG. 1 is a schematic longitudinal cross-sectional view of a gas-fired pulse combustion boiler showing an embodiment of the present invention, and the boiler consists of a gas-fired pulse combustion device 1, a heat exchanger tube 2, a boiler main body 3, a heat exchanger 4, etc. It is composed of
A plurality of pulse combustion devices 1 and heat exchanger tubes 2 are incorporated. The gas-fired pulse combustion device 1 includes a box-shaped combustion chamber body 5 having a combustion chamber A having a rectangular cross-sectional shape, and a mixing chamber B connected to the front wall of the combustion chamber body 5 and communicating with the combustion chamber A. an ignition electrode 7 disposed in the mixing chamber B, an air flap valve 8 that intermittently supplies air to the mixing chamber B, and an ignition electrode connected to the air flap valve 8. An air blower 9, an air intake distribution duct 1 which is interposed between the air flap valve 8 and the air blower 9 and distributes air to each air flap valve 8.
0, a gas flap valve 11 that intermittently supplies gas to the mixing chamber B, and a fuel valve 12 interposed between the gas flap valve 11 and the gas supply source. The heat exchanger tube 2 is made by bending a square pipe having a rectangular cross section, and one end thereof is connected to the rear wall of the combustion chamber body 5 so as to communicate with the combustion chamber A. Each combustion chamber body 5 and each heat transfer tube 2 are immersed in canned water in the boiler main body 3, and the other end of each heat transfer tube 2 penetrates the lower wall of the boiler main body 3 and protrudes outward. There is. Further, a heat exchanger 4 is disposed in a steam chamber 13 formed above within the boiler body 3. Note that the boiler is equipped with sound reduction measures.
That is, each pulse combustion device 1, including the intake port of the blower 9, is entirely surrounded by a cover 14 to prevent noise, and the opening thereof is communicated with an intake noise attenuator 15 installed below the boiler main body 3. . In addition, the length of the heat exchanger tubes 2 is changed so that the exhaust noise of each pulse combustion device 1 cancels each other out, and the outlet side of each heat exchanger tube 2 is communicated with an exhaust noise attenuator 16 installed at the rear of the boiler main body 3. ing. Thus, the pulse combustion boiler mixes the gas supplied to the mixing chamber B through the gas flap valve 11 and the air forcibly blown by the blower 9 in the mixing chamber B, and ignites the mixture. When ignited by electrode 7,
The first combustion takes place. The combustion gas at this time is
The pressure generated by the combustion causes the heat to be discharged from the heat transfer tube 2 and gives heat to the canned water. During this time, gas and air do not flow into the mixing chamber B because the flap valves 8 and 11 are closed. Then, when the combustion gas is exhausted due to exhaust inertia and the combustion chamber A becomes negative pressure, each flap valve 8,
11 is opened, gas and air are naturally drawn into the mixing chamber B, and are re-ignited and combusted by the residual flame. After that, the same cycle as above is repeated 10 to 10 times per second.
Repeated 100 times. Furthermore, even if the cross-sectional shapes of the combustion chamber A and the heat exchanger tubes 2 are rectangular and the heat exchanger tubes 2 are bent, if the volume of the combustion chamber A and the cross-sectional area and length of the heat exchanger tubes 2 are in an appropriate ratio, the stability will be maintained. Pulse combustion can be performed. The table below shows an example.

【table】

[Table] Also, the combustion amount of one pulse combustion device 1 is 30,000 to 40,000 kcal/h due to the relationship between the size of the combustion chamber A and the length of the heat transfer tube 2, etc., and noise reduction.
It is becoming. Therefore, a hot water boiler with a large thermal output is provided with a plurality of pulse combustion devices 1 and heat exchanger tubes 2. (Effects of the invention) As mentioned above, the gas-fired pulse combustion boiler of the invention has rectangular cross-sectional shapes of the combustion chamber and heat exchanger tubes, bends the heat exchanger tubes, and immerses them in canned water inside the boiler body. Because of this structure, the capacity of canned water can be reduced. As a result, the boiler of the present invention is extremely excellent as an energy-saving boiler, as it can shorten the starting time, follow sudden load changes well, and reduce heat radiation loss.

[Brief explanation of the drawing]

Fig. 1 is a schematic vertical sectional view of a gas-fired pulse combustion boiler showing an embodiment of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 shows the combustion chamber body and heat transfer tubes inside the boiler body. FIG. 4 is a cross-sectional view taken along the line -- in FIG. 3, and FIG. 5 is a schematic vertical cross-sectional view of a conventional gas-fired pulse combustion boiler. 1 is a pulse combustion device, 2 is a heat exchanger tube, 3 is a boiler body, and A is a combustion chamber.

Claims (1)

[Scope of utility model registration request] A plurality of units consisting of a combination of a pulse combustion device 1 using gas as fuel and heat exchanger tubes 2 communicated with the combustion chamber A thereof are arranged in parallel, and the combustion chamber A and the heat exchanger tubes 2 of each unit are connected to the boiler main body. In the gas-fired pulse combustion boiler immersed in canned water in the boiler, the cross-sectional shapes of the combustion chamber A and the heat exchanger tubes 2 are formed into a rectangular shape, and the heat exchanger tubes 2 are folded multiple times in the canned water. Bend the end of each heat exchanger tube 2 at the front lower part of the boiler body 3.
A cover 14 surrounds each of the pulse combustion devices 1, and an air intake provided at the bottom of the exhaust silencer 16 below the boiler main body 3 communicates with the exhaust silencer 16 opened upward at the rear of the boiler body 3. A gas-fired pulse combustion boiler characterized in that the boiler communicates with the inside of a sound attenuator 15.